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A year of bloom, from bare weedy ground

A staged plan for northern Delaware — clear the overgrowth this fall, plant in waves, and have something in flower every month of the year. Plus sunflower patches and seed you can actually trust.
Zone 7a/7bNew Castle County, DE
~Apr 8–20Last spring frost
~Nov 4First fall frost (10% risk Oct 21)
~200 daysFrost-free season
Heavy deerEvery plant rated below

Every month, something in flower

۱۲۷ plants that work in zone 7a/7b, each one rated for deer, sun, and whether it's worth growing from seed. Select any plant name to read why it's here. Thick bars are flowers; thin bars are winter structure — berries, stems, seedheads, evergreen foliage.

Start with the ★ plants. Those are the ones you can consider finding first: highest performance, lowest fuss, most months of payoff per dollar. Many come from Mt. Cuba Center in Hockessin — roughly on top of your yard. They grow hundreds of cultivars side by side in your exact soil and deer pressure and score them 1–5.
Month۱۲۷ of ۱۲۷ plants
Sun
Color
Type
Filters
Plant
دید
بهمنب
اسفندا
فروردینف
اردیبهشتا
خردادخ
تیرت
مردادم
شهریورش
مهرم
آبانآ
آذرآ

Flower color, month by month

Actual flowers only — berries, stems, seedheads and evergreen foliage are excluded here, which is why the winter columns look thin. Hover any cell to see which plants deliver that color that month. ✓ = three or more options, ~ = only one or two, — = essentially unavailable.

دیدبهمنباسفندافروردینفاردیبهشتاخردادختیرتمردادمشهریورشمهرمآبانآآذرآ
RedRed in دی: ۳ options, including Hybrid witch hazel،‏ Ozark witch hazel، و Stinking hellebore.Red in بهمن: ۳ options, including Hybrid witch hazel،‏ Ozark witch hazel، و Stinking hellebore.Red in اسفند: ۴ options, including Hybrid witch hazel،‏ Ozark witch hazel،‏ Stinking hellebore، و Japanese andromeda.Red in فروردین: ۳ options, including Stinking hellebore،‏ Japanese andromeda، و Wild columbine.Red in اردیبهشت: ۶ options, including Wild columbine،‏ False indigo،‏ Bearded iris،‏ Peony،‏ Foxglove beardtongue، و Snapdragon.Red in خرداد: ۹ options, including Peony،‏ Foxglove beardtongue،‏ Yarrow،‏ Bee balm،‏ Bachelor's button،‏ Shirley & breadseed poppy،‏ Plains coreopsis، و Snapdragon.Red in تیر: ۱۱ options, including Yarrow،‏ Bee balm،‏ Black-eyed Susan،‏ Crocosmia،‏ Bachelor's button،‏ Shirley & breadseed poppy،‏ Zinnia، و Cosmos.Red in مرداد: ۱۰ options, including Yarrow،‏ Bee balm،‏ Black-eyed Susan،‏ Sneezeweed،‏ Rose mallow،‏ Hardy plumbago،‏ Zinnia، و Cosmos.Red in شهریور: ۹ options, including Red spider lily،‏ Black-eyed Susan،‏ Sneezeweed،‏ Rose mallow،‏ Hardy plumbago،‏ Zinnia،‏ Cosmos، و Plains coreopsis.Red in مهر: ۴ options, including Hardy plumbago،‏ Zinnia،‏ Cosmos، و Snapdragon.Red in آبان: ۳ options, including Zinnia،‏ Cosmos، و Snapdragon.Red in آذر: no options.
OrangeOrange in دی: ۲ options, including Hybrid witch hazel و Ozark witch hazel.Orange in بهمن: ۴ options, including Hybrid witch hazel،‏ Ozark witch hazel،‏ Lenten rose، و Pansies & violas.Orange in اسفند: ۶ options, including Hybrid witch hazel،‏ Ozark witch hazel،‏ Lenten rose،‏ Pansies & violas،‏ Early daffodils، و Hyacinth.Orange in فروردین: ۵ options, including Lenten rose،‏ Pansies & violas،‏ Main-season daffodils،‏ Hyacinth، و Barrenwort.Orange in اردیبهشت: ۷ options, including Pansies & violas،‏ False indigo،‏ Bearded iris،‏ Peony،‏ California poppy،‏ Snapdragon، و Foxglove.Orange in خرداد: ۱۰ options, including Peony،‏ Butterfly weed،‏ Yarrow،‏ Shirley & breadseed poppy،‏ Calendula،‏ Marigold،‏ California poppy، و Snapdragon.Orange in تیر: ۱۴ options, including Butterfly weed،‏ Yarrow،‏ Coneflower،‏ Garden phlox،‏ Black-eyed Susan،‏ Anise hyssop،‏ Shirley & breadseed poppy، و Calendula.Orange in مرداد: ۱۲ options, including Yarrow،‏ Coneflower،‏ Garden phlox،‏ Black-eyed Susan،‏ Anise hyssop،‏ Sneezeweed،‏ Sedum، و Hardy plumbago.Orange in شهریور: ۱۳ options, including Coneflower،‏ Garden phlox،‏ Black-eyed Susan،‏ Anise hyssop،‏ Sneezeweed،‏ Sedum،‏ New England aster، و Hardy plumbago.Orange in مهر: ۱۰ options, including Pansies & violas،‏ Sedum،‏ New England aster،‏ Hardy plumbago،‏ Sheffield mum،‏ Calendula،‏ Zinnia، و Cosmos.Orange in آبان: ۷ options, including Pansies & violas،‏ Sheffield mum،‏ Calendula،‏ Zinnia،‏ Cosmos،‏ Marigold، و Snapdragon.Orange in آذر: ۱ options, including Pansies & violas.
YellowYellow in دی: ۶ options, including Hybrid witch hazel،‏ Ozark witch hazel،‏ Winter aconite،‏ Winter jasmine،‏ Wintersweet، و Mahonia 'Winter Sun'.Yellow in بهمن: ۱۲ options, including Hybrid witch hazel،‏ Ozark witch hazel،‏ Winter aconite،‏ Lenten rose،‏ Winter jasmine،‏ Wintersweet،‏ Paperbush، و Amur adonis.Yellow in اسفند: ۱۵ options, including Hybrid witch hazel،‏ Ozark witch hazel،‏ Lenten rose،‏ Winter jasmine،‏ Wintersweet،‏ Paperbush،‏ Amur adonis، و Cornelian cherry.Yellow in فروردین: ۹ options, including Lenten rose،‏ Paperbush،‏ Pansies & violas،‏ Main-season daffodils،‏ Hyacinth،‏ Winter hazel،‏ Forsythia، و Barrenwort.Yellow in اردیبهشت: ۸ options, including Pansies & violas،‏ Wild columbine،‏ False indigo،‏ Siberian iris،‏ Bearded iris،‏ Peony،‏ California poppy، و Snapdragon.Yellow in خرداد: ۱۲ options, including Siberian iris،‏ Peony،‏ Smooth hydrangea،‏ Threadleaf coreopsis،‏ Butterfly weed،‏ Yarrow،‏ Calendula، و Marigold.Yellow in تیر: ۱۵ options, including Smooth hydrangea،‏ Threadleaf coreopsis،‏ Butterfly weed،‏ Yarrow،‏ Black-eyed Susan،‏ Panicle hydrangea،‏ Calendula، و Zinnia.Yellow in مرداد: ۱۱ options, including Threadleaf coreopsis،‏ Yarrow،‏ Black-eyed Susan،‏ Panicle hydrangea،‏ Sneezeweed،‏ Zinnia،‏ Cosmos، و Four o'clocks.Yellow in شهریور: ۱۱ options, including Black-eyed Susan،‏ Panicle hydrangea،‏ Sneezeweed،‏ Goldenrod،‏ Calendula،‏ Zinnia،‏ Cosmos، و Four o'clocks.Yellow in مهر: ۱۱ options, including Common witch hazel،‏ Pansies & violas،‏ Panicle hydrangea،‏ Goldenrod،‏ Sheffield mum،‏ Calendula،‏ Zinnia، و Cosmos.Yellow in آبان: ۹ options, including Common witch hazel،‏ Mahonia 'Winter Sun'،‏ Pansies & violas،‏ Sheffield mum،‏ Calendula،‏ Zinnia،‏ Cosmos، و Marigold.Yellow in آذر: ۵ options, including Common witch hazel،‏ Winter jasmine،‏ Wintersweet،‏ Mahonia 'Winter Sun'، و Pansies & violas.
PinkPink in دی: ۲ options, including Christmas rose و Cyclamen.Pink in بهمن: ۳ options, including Christmas rose،‏ Lenten rose، و Cyclamen.Pink in اسفند: ۷ options, including Lenten rose،‏ Cyclamen،‏ Glory-of-the-snow،‏ Grecian windflower،‏ Hyacinth،‏ Lungwort، و Japanese andromeda.Pink in فروردین: ۱۳ options, including Lenten rose،‏ Glory-of-the-snow،‏ Grecian windflower،‏ Hyacinth،‏ Lungwort،‏ Japanese andromeda،‏ Eastern redbud، و Moss phlox.Pink in اردیبهشت: ۱۰ options, including Ornamental onion،‏ Creeping phlox،‏ Foamflower،‏ Fringed bleeding heart،‏ Peony،‏ Meadow sage،‏ Larkspur، و California poppy.Pink in خرداد: ۱۶ options, including Ornamental onion،‏ Fringed bleeding heart،‏ Peony،‏ Meadow sage،‏ Smooth hydrangea،‏ Yarrow،‏ Balloon flower، و Bee balm.Pink in تیر: ۱۹ options, including Fringed bleeding heart،‏ Smooth hydrangea،‏ Yarrow،‏ Balloon flower،‏ Coneflower،‏ Garden phlox،‏ Bee balm، و Summersweet.Pink in مرداد: ۱۶ options, including Fringed bleeding heart،‏ Yarrow،‏ Balloon flower،‏ Coneflower،‏ Garden phlox،‏ Bee balm،‏ Summersweet، و Panicle hydrangea.Pink in شهریور: ۱۵ options, including Autumn crocus،‏ Fringed bleeding heart،‏ Coneflower،‏ Garden phlox،‏ Panicle hydrangea،‏ Joe Pye weed،‏ Rose mallow، و Sedum.Pink in مهر: ۱۱ options, including Panicle hydrangea،‏ Sedum،‏ New England aster،‏ Japanese anemone،‏ Sheffield mum،‏ Fall-blooming camellia،‏ Zinnia، و Cosmos.Pink in آبان: ۶ options, including Christmas rose،‏ Sheffield mum،‏ Fall-blooming camellia،‏ Zinnia،‏ Cosmos، و Snapdragon.Pink in آذر: ۲ options, including Christmas rose و Fall-blooming camellia.
PurplePurple in دی: no options.Purple in بهمن: ۴ options, including Lenten rose،‏ Pansies & violas،‏ Reticulated iris، و Snow crocus.Purple in اسفند: ۵ options, including Lenten rose،‏ Pansies & violas،‏ Reticulated iris،‏ Snow crocus، و Hyacinth.Purple in فروردین: ۸ options, including Lenten rose،‏ Pansies & violas،‏ Hyacinth،‏ Moss phlox،‏ Woodland phlox،‏ Creeping phlox،‏ Barrenwort، و Money plant.Purple in اردیبهشت: ۱۵ options, including Pansies & violas،‏ Camassia،‏ Ornamental onion،‏ Woodland phlox،‏ Creeping phlox،‏ False indigo،‏ Siberian iris، و Bearded iris.Purple in خرداد: ۱۱ options, including Ornamental onion،‏ Siberian iris،‏ Catmint،‏ Meadow sage،‏ Hardy geranium،‏ Bee balm،‏ Larkspur، و Love-in-a-mist.Purple in تیر: ۱۳ options, including Catmint،‏ Hardy geranium،‏ Garden phlox،‏ Bee balm،‏ Blazing star،‏ Anise hyssop،‏ Russian sage، و Love-in-a-mist.Purple in مرداد: ۱۳ options, including Catmint،‏ Hardy geranium،‏ Garden phlox،‏ Bee balm،‏ Blazing star،‏ Anise hyssop،‏ Ironweed، و Bluebeard.Purple in شهریور: ۱۶ options, including Autumn crocus،‏ Catmint،‏ Hardy geranium،‏ Garden phlox،‏ Anise hyssop،‏ Ironweed،‏ Bluebeard، و Russian sage.Purple in مهر: ۱۱ options, including Pansies & violas،‏ Catmint،‏ Hardy geranium،‏ Aromatic aster،‏ New England aster،‏ Smooth aster،‏ Toad lily، و Zinnia.Purple in آبان: ۴ options, including Pansies & violas،‏ Aromatic aster،‏ Zinnia، و Sweet alyssum.Purple in آذر: ۱ options, including Pansies & violas.
True blueTrue blue in دی: no options.True blue in بهمن: ۱ options, including Reticulated iris.True blue in اسفند: ۷ options, including Reticulated iris،‏ Siberian squill،‏ Glory-of-the-snow،‏ Puschkinia،‏ Grecian windflower،‏ Hyacinth، و Lungwort.True blue in فروردین: ۱۱ options, including Siberian squill،‏ Glory-of-the-snow،‏ Puschkinia،‏ Grecian windflower،‏ Grape hyacinth،‏ Hyacinth،‏ Lungwort، و Moss phlox.True blue in اردیبهشت: ۱۱ options, including Camassia،‏ Woodland phlox،‏ Siberian bugloss،‏ False indigo،‏ Bluestar،‏ Siberian iris،‏ Bearded iris، و Catmint.True blue in خرداد: ۸ options, including Siberian iris،‏ Catmint،‏ Hardy geranium،‏ Balloon flower،‏ Larkspur،‏ Bachelor's button،‏ Love-in-a-mist، و Borage.True blue in تیر: ۱۰ options, including Catmint،‏ Hardy geranium،‏ Balloon flower،‏ Anise hyssop،‏ Globe thistle،‏ Russian sage،‏ Anise sage، و Bachelor's button.True blue in مرداد: ۱۰ options, including Catmint،‏ Hardy geranium،‏ Balloon flower،‏ Anise hyssop،‏ Globe thistle،‏ Bluebeard،‏ Russian sage، و Anise sage.True blue in شهریور: ۹ options, including Catmint،‏ Hardy geranium،‏ Anise hyssop،‏ Bluebeard،‏ Russian sage،‏ Anise sage،‏ Smooth aster، و Hardy plumbago.True blue in مهر: ۵ options, including Catmint،‏ Hardy geranium،‏ Anise sage،‏ Smooth aster، و Hardy plumbago.True blue in آبان: no options.True blue in آذر: no options.
WhiteWhite in دی: ۴ options, including Snowdrops،‏ Christmas rose،‏ Wintersweet، و Cyclamen.White in بهمن: ۹ options, including Snowdrops،‏ Christmas rose،‏ Lenten rose،‏ Wintersweet،‏ Sweet box،‏ Paperbush،‏ Cyclamen، و Pansies & violas.White in اسفند: ۱۸ options, including Snowdrops،‏ Lenten rose،‏ Wintersweet،‏ Sweet box،‏ Paperbush،‏ Cyclamen،‏ Pansies & violas، و Snow crocus.White in فروردین: ۲۱ options, including Lenten rose،‏ Paperbush،‏ Pansies & violas،‏ Main-season daffodils،‏ Siberian squill،‏ Glory-of-the-snow،‏ Puschkinia، و Grecian windflower.White in اردیبهشت: ۱۷ options, including Pansies & violas،‏ Camassia،‏ Ornamental onion،‏ Foamflower،‏ Fringed bleeding heart،‏ False indigo،‏ Siberian iris، و Bearded iris.White in خرداد: ۲۲ options, including Ornamental onion،‏ Fringed bleeding heart،‏ Siberian iris،‏ Peony،‏ Meadow sage،‏ Foxglove beardtongue،‏ Smooth hydrangea، و Virginia sweetspire.White in تیر: ۲۳ options, including Fringed bleeding heart،‏ Smooth hydrangea،‏ Yarrow،‏ Balloon flower،‏ Coneflower،‏ Garden phlox،‏ Bee balm، و Blazing star.White in مرداد: ۱۷ options, including Fringed bleeding heart،‏ Yarrow،‏ Balloon flower،‏ Coneflower،‏ Garden phlox،‏ Bee balm،‏ Blazing star، و Summersweet.White in شهریور: ۱۷ options, including Autumn crocus،‏ Fringed bleeding heart،‏ Coneflower،‏ Garden phlox،‏ Panicle hydrangea،‏ Rose mallow،‏ White wood aster، و Japanese anemone.White in مهر: ۱۴ options, including Pansies & violas،‏ Panicle hydrangea،‏ White wood aster،‏ Japanese anemone،‏ Toad lily،‏ Fall-blooming camellia،‏ Calendula، و Zinnia.White in آبان: ۹ options, including Christmas rose،‏ Pansies & violas،‏ Fall-blooming camellia،‏ Calendula،‏ Zinnia،‏ Cosmos،‏ Marigold، و Sweet alyssum.White in آذر: ۴ options, including Christmas rose،‏ Wintersweet،‏ Pansies & violas، و Fall-blooming camellia.

Sunflower patches

You have room for real height and a wild color range. The plan below gets you blooms from late July through mid-October, in gold, burgundy, chestnut, cream, orange and near-black, from about $30 of seed.

Direct-sow, don’t transplant

Sunflowers put down a taproot about 4 ft deep. That taproot is exactly what keeps a 12-ft plant standing in an August thunderstorm, and a cell tray ruins it. Sow in place and protect the seed instead.

Wait for 60°F soil

Roughly May 1–10 here. Sowing into cold wet soil is the specific condition that causes downy mildew — the #1 killer of home sunflower patches. Buy a $10 soil thermometer; it’s the cheapest insurance in this whole plan.

Don’t feed them much

NDSU found lodging severity is directly related to nitrogen rate, and that high N also worsens rust, white mold and downy mildew. You want good soil — deep, well-drained, compost-amended — not a fertilizer program. Skip side-dressing once buds form.

Succession sowing schedule for New Castle County

Branching varieties every 2–3 weeks, single-stem every 10 days. Single-stem types give you one flower and are done in about 10 days — branching types carry weeks of bloom per plant, which is what you want for a patch.

SowDateWhatBlooms
1~May 1–10
first 60°F soil
All the giants (Mammoth, Titan, Skyscraper, American Giant, Kong) + long-season branchers (Autumn Beauty, Evening Sun, Velvet Queen)Giants late Jul–Aug; branchers Aug–Sep
2~May 20–25Mid-season branching: Soraya, Ring of Fire, Moulin Rouge, Italian White, Strawberry BlondeLate July onward
3~June 10Repeat branching mix + first fast singles (Ruby Eclipse, ProCut)Mid-Aug onward
4~June 25Branching + fast singlesSeptember
5~July 10Last call for 90–100 day varietiesSep–Oct
6~July 25Fast types only — Cherry Rose (40d), Ruby Eclipse (55d), ProCut (50–60d)Late Sep–Oct
7~Aug 5 — last safe sowingCherry Rose / ProCut onlyEarly–mid Oct

Spacing and how much seed to actually buy

Spacing

  • Giants: 24 in apart, minimum. Crowd them and you get 7-ft plants with 6-in heads instead of 10-ft plants with 12-in heads.
  • Branching in a patch: 12–18 in, scattered in an offset grid rather than rows.
  • Depth: a full 1 inch. Deeper sowing is itself partial defense against jays and squirrels.

Seed quantity — the honest math

Bulk vendors quote a broadcast rate of 1 lb per 500 sq ft. That assumes scattered seed that gets eaten and never thinned. If you sow deliberately and protect it:

  • 300 sq ft of giants at 24 in = ~75 plants. Two seeds per station plus spares ≈ 1 oz.
  • 300 sq ft of branching at 18 in = ~133 plants ≈ ½ oz (Autumn Beauty runs ~719 seeds/oz).
  • A mixed 400 sq ft patch: budget 2–3 oz total across 6–8 varieties.

Buying a pound to plant 300 sq ft is the same false economy as a shaker can.

Varieties

OP = open-pollinated, saved seed comes roughly true. F1 = hybrid, saved seed won’t. Note that even OPs cross freely in a mixed patch — saved seed from Autumn Beauty next to Velvet Queen will be a mongrel. Usually a gorgeous one.

Mammoth Grey Stripe
OP
9–12 ft · 90–100 days · head 8–14 in
Single stem · Pollen
The workhorse giant and the best bird-food head. 9–10 ft is a realistic Delaware result; 12 ft needs everything to go right. Big seed — only ~188 per ounce, so an ounce plants a large patch.
Titan
OP
10–14 ft · 90–110 days · head up to 24 in
Single stem · Pollen
The biggest published head of the lot, but note the catalog hedge — 24 in is best case. Long season: must be sown by early June here. Baker Creek says it typically needs staking.
American Giant
F1
8–15 ft · 70 days · head ~10 in
Single stem · Pollen
★ Best tall-plus-sturdy pick. Harris says it 'resists lodging better than other giant types,' and at 70 days it's the fastest giant, so you can sow it later. F1 — saved seed won't come true.
Skyscraper
OP
12 ft · 75–80 days · head 14 in
Single stem · Pollen
Best height-to-days ratio: 12 ft in 75–80 days. Hudson Valley says it tolerates poor soil and irregular watering. Stake it.
Kong
F1
8–15 ft · Late days · head many medium heads
Branching ·
The outlier — a giant BRANCHING type sold for making 'tall hedge walls.' Perfect for the back edge of a patch; wrong if you want one enormous head.
Russian Mammoth
OP
10–12 ft · Late days · head up to 20 in
Single stem · Pollen
Functionally interchangeable with Mammoth Grey Stripe. 'Mammoth,' 'Russian Mammoth' and 'Grey Stripe' are loosely applied names — buy on the vendor's stated height, not the name.
Autumn Beauty
OP
6–7 ft · 70–100 days · head 6–8 in
Branching · Pollen
★ The single best variety for a wild mix of colors — yellow, bronze, burgundy, rust, and many bicolors on one packet. Branching means weeks of bloom per plant instead of days. ⚠ Some vendors market it as 'deer resistant.' That is false.
Velvet Queen
OP
5–7 ft · 70–100 days · head 5–8 in
Branching, multi-headed · Pollen
Deep chestnut-burgundy with dark centers. Reads almost black in low sun. Stake even at 5–6 ft.
Evening Sun
OP
7 ft · 80–100 days · head medium–large
Branching · Pollen
Crimson, rust, bronze and gold bicolors. Similar spirit to Autumn Beauty with more red in the mix.
Ring of Fire
OP
4 ft · ~75 days · head 5–6 in
Branching ·
All-America Selections winner. Gold petals with a dark red ring around the center. Compact enough for the front of a patch.
Moulin Rouge
F1
4–8 ft · 65–75 days · head 5–8 in
Branching · Pollenless
The darkest sunflower generally available — velvety burgundy, near-black at the disk. Pollenless, so no drop on a table.
Italian White
OP
5 ft · 65–75 days · head ~4 in
Branching · Pollen
Creamy white with a chocolate center. Heirloom, sturdy, and the odd one out in a patch of gold and red — which is exactly why to grow it.
Ruby Eclipse
F1
5–6 ft · 55–65 days · head 4–5 in
Branching · Pollenless
Ruby shading to dusty rose and cream. Fast — good for later sowings.
Strawberry Blonde
F1
5 ft · 65–75 days · head
Branching · Pollenless
Burgundy-pink petals with ivory tips. Genuinely unusual coloring.
Cherry Rose
F1
4–5 ft · 40 days · head 3–4 in
Branching · Pollenless
★ 40 days to bloom — the fastest thing here, and therefore your last-sowing variety for October flowers.
Soraya
OP
6 ft · 80 days · head 4–6 in, up to 25 blooms
Sturdy branching · Nearly pollenless
Deep luminous orange, mahogany disk, up to 25 blooms per plant. The first sunflower ever to win an AAS award.
Lemon Queen
OP
5–10 ft · ~100 days · head 4–8 in
Branching clusters · Pollen
Pure lemon-yellow, and the Great Sunflower Project's standard pollinator variety. Doesn't start until late August — from one May sowing that's a September–October show.
Teddy Bear
OP
24–36 in · ~75 days · head 3–5 in
Multi-branching · Minimal
Fully double golden pompoms at knee height. The one to plant along a path edge or with kids.
ProCut series
F1
5–6 ft · 50–60 days · head 4–6 in
Single stem · Pollenless
The florist standard: uniform, fast, pollenless, in orange, red, plum, white and bicolors. Single-stem — one flower per plant — so sow every 10 days if you use these. 'Gold Lite DMR' and 'Orange DMR' are downy-mildew resistant, worth it in a wet spring.
Swamp sunflower
Perennial
5–8 ft · Mid–late summer into fall days · head 2–3 in
Perennial, branching · Pollen
Helianthus angustifolius — a hardy PERENNIAL sunflower that flowers into October, zones 5–9. ⚠ Spreads aggressively by rhizome and flops without a June cutback. Plant it outside the annual patch.

The three things that actually kill a sunflower patch

1. Birds & squirrels, days 1–10

This is the #1 cause of failure and it happens before anything comes up. Fix: lay floating row cover or ¼-in hardware cloth flat over the sown area, pinned down, and lift it at the two-true-leaf stage. Sow a full inch deep. Sow more than you need. Move bird feeders away from the patch during that window.

2. Deer, weeks 1–6

Rutgers rates Helianthus as C — often preferred, requires protection. (Ignore any vendor claiming Autumn Beauty is "deer resistant." It isn’t.) Deer strip 6–18 in seedlings; a 9-ft plant just loses lower leaves. So you only need to defend the first month or so: 7-ft deer netting on 8-ft posts, or weekly egg-based repellent (3 whole eggs blended into a gallon of water, reapplied every two weeks and after rain).

3. Wind on top-heavy giants

Stake anything over 10 ft. But don’t stake individually — corral: 8-ft T-posts at the corners and every 6–8 ft, with two horizontal courses of twine at ~3 ft and ~5–6 ft. The block supports itself. Drive stakes at sowing time; driving one next to a mature giant severs the taproot.

Japanese beetles, early July. They aggregate on sunflower heads and it’s a real Mid-Atlantic problem. Penn State’s verdict: handpicking into soapy water early morning genuinely works at this scale, and traps are explicitly not recommended — they pull more beetles into your yard than they catch. Do not spray systemics on open heads; a sunflower patch is a pollinator magnet and that’s the whole point. Damage ends by early August, so later sowings escape it entirely.
Allelopathy is real, but don’t overread it. Sunflower leaf litter measurably suppresses germination of small-seeded broadleaf plants — and has little or no effect on grasses. Practical upshot: don’t direct-sow small annual seed into the sunflower footprint, do use transplants nearby if you want companions, and rake up sunflower debris at season’s end (which also handles rust and white-mold sanitation). Most of what gardeners blame on allelopathy is just a 12-ft plant casting shade and drinking all the water.
After bloom: leave most heads standing. Goldfinches, chickadees, titmice and cardinals will work them from September into winter, and the hollow stalks host overwintering native bees. Bag only the 5–10 heads you want seed from — tulle netting works best; paper bags mold in a humid Delaware September. The one exception: if you had rust or any white mold, sanitation wins — cut and remove everything.

Clearing the ground

Mid-August is close to the perfect moment to start. Fall is the best herbicide window if you use any, September–October is Delaware’s best planting season, and a cardboard-and-mulch bed laid down in September is ready to plant in April. But the honest part first: smothering is a turf-and-annual-weed tool.It does not fix established perennial weeds in one winter, and anyone telling you otherwise hasn’t read the extension literature.

Step one: triage into three zones. This decides everything.

Zone 1 — turf & annual weeds

Grass, crabgrass, ordinary broadleaf weeds, nothing woody.

Method: sheet mulch in September.
Plantable: April.

Zone 2 — perennial weeds

Mugwort, bindweed, Canada thistle, English ivy, nutsedge, quackgrass.

Method: black silage tarp, months not weeks.
Plantable: spring of year 2 at the earliest. If bindweed is in it, years 2–5.

Zone 3 — woody invasives

Tree-of-heaven, Oriental bittersweet, multiflora rose, wineberry, knotweed, poison ivy.

Method: targeted, on its own schedule. Start now — July–September is peak translocation to the roots.
Plantable: after it’s actually dead.

The single most useful thing on this page: don’t promise yourself spring planting in Zone 2. Deciding that up front is what separates a project that works from one that gets abandoned in year two. Do Zone 1 beautifully this year and let Zone 2 cook.

Zone 1: sheet mulching, the method that works

  1. Mow or scalp it short and rake the biomass off. Virginia Tech found leaving thatch under a cover actually insulates the soil and makes the treatment worse.
  2. Edge the bed — dig a shallow trench around the perimeter so you can tuck the cardboard edges in. Wind lifting an edge is the #1 failure mode.
  3. Plain brown corrugated only. No glossy printing, no waxed produce boxes, no white/bleached boxes (PFAS coatings). Remove all tape and staples. Free from appliance stores, bike shops, furniture stores.
  4. Soak the cardboard thoroughly as you lay it. This is the step everyone skips and it matters — dry cardboard sheds water instead of letting it through.
  5. Overlap 8–10 inches, leaving no gaps.
  6. 4–6 inches of mulch or compost on top. More is better.
  7. Wait. Laid in September, it’s plantable in April. Plant through it: scrape the mulch aside, put roots in actual soil, pull the mulch back. Never till — tilling resurrects the seedbank you just buried.
A real disagreement worth knowing about. WSU’s Linda Chalker-Scott argues cardboard is the wrong material entirely — linerboard is manufactured to resist moisture and gas diffusion, and she cites research that one layer of cardboard is ten times worse for gas exchange than 4 in of wood chips. Her alternative:6–12 inches of coarse arborist wood chips, no cardboard at all. If you can get free chips from a local tree crew — call two or three, they often dump for free — that route sidesteps the whole argument and costs nothing. The middle path: plain soaked cardboard plus a deep 6-in chip layer, so the chips do most of the work.

Zone 2: tarping, and how long it really takes

Use a real silage tarp (5–6 mil, black/white, UV-inhibited), black side up, weighted with sandbags at every edge and across the middle. Do not use hardware-store black poly — it photodegrades within a year and shatters into a thousand pieces you’ll be picking out of the soil forever.

TargetTime under tarp
Actively growing annual weeds, midsummerUnder 1 week
Annual weeds, cool seasonUp to 3 weeks
Killing a cover crop or established turf3–5 weeks
Bermudagrass / johnsongrass, summer14–16 weeks
Canada thistle, Japanese knotweedA year or longer

What survives a tarp: nutsedge is the headline survivor — it literally punctures polyethylene with its sharp leaf tips. Mugwort and dandelion also showed resilience in Virginia Tech’s trials. Bindweed needs the cover left in place 1 to 5 years, extended several feet past the visible patch. And purslane and crabgrass can actually increase after tarping.

Zone 3: the ones smothering won’t touch

SpeciesDoes smothering work?What actually works
Tree-of-heavenNo — cutting makes it worseBasal bark or hack-and-squirt with triclopyr, July–September only. Cutting triggers dozens of root suckers. Also the preferred host of spotted lanternfly, which is endemic in your county.
Japanese knotweedEffectively noA systematic review found regrowth in 78% of tarping attempts; only 6 of 22 operations achieved eradication. Penn State’s program: cut late May, cut again mid-July, foliar-treat in late summer, repeat for years.Never dig or move the soil — fragments propagate.
Oriental bittersweetNoCut the vines, allow 8 weeks of regrowth, then foliar-treat after July 1. Cutting alone only works if you repeat it until the roots exhaust — miss one season and it recovers.
Multiflora roseNoCut-stump with concentrated glyphosate within 10 minutes of cutting, or basal bark. Then expect to pull seedlings for years — the seedbank stays viable up to 20 years.
MugwortPartiallyUMD calls it "very difficult." Combination approach over 2+ seasons. The load-bearing rule:never till it — every root fragment becomes a new plant.
Field bindweedYes, in 1–5 yearsRoots go 30 ft deep. Cover for years, extending well past the visible patch, or pull every 2–3 weeks for 2–7 years. Not a joke.
Canada thistleA year+Fall herbicide applications consistently beat spring. 2–4 years. Never till — a root fragment ¼ inch long makes a new plant.
English ivyYes, slowlySmother, plus cut all vines off tree trunks at chest height and at the base. Spray in spring when 3–5 new leaves show — before the waxy cuticle forms. ⚠ Also illegal to sell or propagate in Delaware since 2022.
Poison ivyProbably (shallow roots)Dig or pull small plants; cut vines on trees and treat the cut end immediately. Never burn it.Dead plants stay hazardous for up to two years — including the cardboard you pull off it later.
NutsedgeNo — it pierces plasticTubers sit 8–14 in deep and survive 1–3 years; one tuber resprouts 10–12 times. Pull every shoot before it reaches 5 leaves, forever, or use halosulfuron.

What it costs, for 300 sq ft

Sheet-mulch route (Zone 1)

  • Cardboard — $0 (about 30–40 large flattened boxes)
  • 4 cu yd leaf compost/mulch at ~$31/yd picked up — $124
  • Landscape staples and sandbags — ~$20

Total: ~$145 self-haul, ~$250–300 delivered. Bulk suppliers just over the PA line (Trainer / Chester County) serve northern Delaware; mushroom soil runs even cheaper at ~$26/yd but is salty when fresh — use it as a topdress, not a seedbed.

Tarp route (Zone 2)

  • 12′×20′ backyard silage tarp (240 sq ft) — $65
  • OR a 24′×100′ roll (2,400 sq ft) — $130
  • Sandbags/weights — $30–60. Do not cheap out here; wind is the #1 tarp failure.

Total: $95–190, and the tarp is reusable for years. Note the math: the big roll is 5¢/sq ftversus 27¢/sq ft for small backyard tarps, with a better UV rating. Over ~500 sq ft, buy the roll.

Delaware’s Invasive Plants Law (effective July 2022) bans importing, selling, transporting or propagating listed species — including English ivy, periwinkle, Japanese pachysandra, Callery pear, Norway maple, Japanese barberry, burning bush, privet and Chinese wisteria. Fines run $50–$500 per occurrence. Worth checking the current Department of Agriculture list before you buy any shrub, and before you move any plant material off your property.

Why those seed packs failed you

It probably wasn’t your fault, and the reason is structural: home-garden seed packets are legally allowed to tell you almost nothing.

Delaware law (3 Del. C. § 1502B), for packets under a pound, requires only: the kind and variety, a lot ID, the labeler’s name and address, and the phrases "Sell by" and "Packed for [year]."A germination percentage and test date are required only if the seed falls below the state minimum — in which case the packet must also say "below standard" in 8-point type. So "Packed for 2026" means the seed waspackaged this season. It does not mean it was tested this season, and it tells you nothing about what it tested at.

And the legal minimums are low

Federal minimum germination standards are laboratory numbers under ideal conditions. Field performance is much worse, and the gap widens sharply at the bottom: seed testing at 95% in a lab might give ~65% in real soil, while seed at the 75% legal minimum can collapse to roughly 15% field emergence. Pepper and carrot minimums are55%. Spinach is 60%. That’s legal seed.

The one thing to look for: a printed germination % and test month/year on the packet. Nobody has to give you that. A company that voluntarily prints it is signaling confidence — and it’s the single best proxy for quality available to a consumer. Johnny’s and Stokes do this. Most consumer brands don’t.

Who to buy from

Tier 1 — documented testing, pro-grower customers

Johnny’s Selected Seeds (Maine) — the default for Northeast market gardeners. Labels germination data even on small packets, and sells in graduated bulk (packet → 1/16 oz → oz → lb), which makes them cost-competitive at patch scale. The strongest all-round choice for cut-flower annuals and sunflowers.

High Mowing Organic Seeds(Vermont) — the best-documented QC of anyone. In-house lab, germination + purity + vigor tests on every lot, retested every 4–6 months, and they’ve raised standards above federal: sweet pepper at 75–85% versus the 55% legal floor. Five-person quality team under a PhD manager.

Stokes Seeds — prints germination results on every package using soil-based testing, not just paper-towel lab germ. The most stringent disclosure practice among the companies surveyed here.

Tier 2 — good reputations, worth your money

Botanical Interests — the best-designed consumer packets in the business; the inside panel is a genuine growing guide. Third-party lab tested, no fillers, never treated. Best pick for a beginner. (Acquired by Epic Gardening in 2023 — no evidence of decline, but worth watching.)

Southern Exposure Seed Exchange (Virginia) — the most regionally relevant company for you. Varieties selected for Mid-Atlantic heat and humidity, which is not the same thing as varieties bred for Oregon or Maine.

Hudson Valley Seed Co. (NY) andFedco (Maine) — Northeast-adapted, reasonably priced. Fedco is very cheap; Hudson Valley charges a premium for the art packets.

Select Seeds (Connecticut) — heirloom and antique flowers specifically, including fragrant cottage annuals. Long-standing high customer ratings.

Pinetree Garden Seeds — small packets at low prices, explicitly for home gardeners who don’t want 200 seeds. Best value per packet at small scale.

Best for bulk flower seed by weight

Once you’re planting a patch rather than a row, packets are wildly uneconomical.

  • Johnny’s — graduated bulk sizes on named cut-flower varieties (Benary’s Giant zinnias, ProCut sunflowers). Best quality-per-dollar at scale.
  • Harris Seeds — commercial cut-flower seed in bulk, Rochester NY.
  • Applewood Seed Co. — an actual producer, not a reseller; they grow and clean their own.
  • Eden Brothers — the main US source for bulknamed-variety sunflower seed. Solid refund policy on non-germination.
  • Jelitto — the professional standard forperennial seed, with published germination protocols per species and pre-treated seed for the hard ones.

Best for native Mid-Atlantic seed

  • Ernst Conservation Seeds (Meadville, PA) —the best fit for you by a wide margin. Largest native seed producer in the eastern US. Their Mesic-to-Dry Native Pollinator Mix is ~$42/lb for 29 species, sown at 20 lb/acre — meaning 300 sq ft needs about 0.14 lb, roughly $6 of seed. That is the entire argument for buying native seed by weight from a producer instead of in shaker cans. Call them first; they’re oriented to contractors.
  • Prairie Moon Nursery — best documentation in the business, ships a germination-codes sheet with every order, source-identified ecotypes, no cultivars. Caveat: upper-Midwest genetics. Use Ernst for the bulk matrix, Prairie Moon for individual hard-to-find species.
  • Brandywine Conservancy (Chadds Ford, PA) — seeds by mail order, ~25 minutes from you.

What to stop buying

"Wildflower mix" shaker cans

Four specific failure modes, all documented:

  • Filler. A 2 oz can may hold a small fraction of an ounce of actual seed — the rest is sand or "fluff." This is why the coverage claims are absurd.
  • Annual-heavy. They lean on alyssum, calendula and baby’s breath: spectacular in year one, gone in year two. You expected a meadow and bought a one-season display.
  • Geographic mismatch and weeds. Mixes routinely include species from thousands of miles away, and studies find weedy or invasive content — Siberian wallflower, oxeye daisy, and worse.
  • They ignore stratification. Most true natives need a cold-moist winter to germinate at all. Spring-sow a can of native seed and nothing comes up, and you conclude the seed was dead.

Also skip

Big-box rack seed and dollar-store packets. No germination disclosure required, lots only need to clear a low federal minimum, and the rack sits in an unconditioned garden center through a Delaware July — seed longevity is a function of heat × humidity, and that’s near worst case. Retailers also recirculate last year’s stock. Fine for beans, peas, radishes, zinnias, sunflowers you’re sowing thickly.A false economy for anything slow, expensive, or where you need a specific number of plants.

Amazon third-party sellers. You can’t see a seed tag before buying, there’s no lot traceability, and the "brand" is often a reseller repacking unknown bulk. There’s a documented ecosystem of listings using AI-generated images of flowers that don’t exist. Amazon restricted seed sales to US-based sellers in 2020 after the mystery-seed incident — that constrains who lists, not what’s in the envelope.

Seed bombs and seed mats. Light-requiring seeds sealed inside a clay ball may never germinate at all, and the whole premise is that you skip site prep — which is the entire game.

Two habits that will fix this permanently.
1. Buy in December–January, direct from the company. Good varieties sell out, and you get fresh-lot seed rather than late-season leftovers off a hot rack.
2. Test a questionable lot yourself. Ten seeds on a damp paper towel in a zip bag at room temperature. Count sprouts at the expected days-to-germination. Ten seeds gives you 10% resolution — plenty to tell "fine" from "garbage" before you commit a season to it.
For anything sold by weight, compare on Pure Live Seed, not price per pound.PLS = purity % × germination % ÷ 100. Penn State’s worked example: seed at $1.95/lb with 51% PLS actually costs $3.90/lb of viable seed, versus $3.30/lb for "premium" seed at $2.50/lb and 89% PLS. The cheap seed is 18% more expensive. A proper tag discloses purity, germination, inert matter, weed seed and other crop seed — andinert matter % is your filler detector.

Where to actually buy this

Three Delaware organizations cover almost all of it, and they are not interchangeable — they do different jobs. One tells you which plant performs, one sells you the plant cheaply, one is a volunteer network. Knowing which is which saves real money.

Delaware Nature Society — where you buy

DelNature’s Native Plant Sale runs twice a year, spring and fall, and it is the single cheapest legitimate source of native plants in the state. Most herbaceous plants — flowers, grasses, ferns — run $12–17; most shrubs and trees run $25–50. Compare that to $28–40 for the same perennial in a garden center.

Two locations. Coverdale Farm Preserve in Greenville is the northern one and is close to you. Abbott’s Mill Nature Center in Milford serves southern Delaware.

Members get a preview day the afternoon before the public opens. At a sale where availability changes hour to hour, that is the real value of the membership — a $25–50 shrub you actually wanted beats one you settled for.

Practical notes: entry is free, they take cards, checks and cash, and they tell you outright to bring your own wagon because theirs run out. The catalog covers most but not all of what shows up, and prices are set close to the day.

DelNature has been running this sale for over three decades and is the Delaware state affiliate of the National Wildlife Federation.

Mt. Cuba Center — where you find out what works

Mt. Cuba’s trial garden in Hockessin is the reason this page can tell you that Phlox’Jeana’ is worth planting and most garden phlox isn’t. They grow hundreds of cultivars side by side in your soil, under your deer pressure, and score them 1–5 over several years. That is research output, freely published, and there is nothing else like it within an hour’s drive.

They also sell plants and hold their own sales — but the reason they matter to you is the data. Read the trial reports before you spend anything. Every ★ on this page traces back to one.

Two more worth knowing

Delaware Native Plant Society — a separate, smaller, volunteer-run organization that also holds plant sales and native plant events. Worth being on their list: small sales sometimes carry straight species the bigger operations skip, and the people staffing the tables tend to be the ones who actually grew the plants.

Native Plant Nurseries Serving Delaware — a free directory of retail and wholesale native nurseries, published by the Delaware Nursery & Landscape Association with the state Department of Agriculture and UD Cooperative Extension. This is where you go for the things the sales don’t carry — the witch hazel hybrids below, specific Mt. Cuba cultivars, or anything you need outside of two Saturdays a year.

What DelNature does that nobody else does

The catalog flags plants as “Species of Greatest Conservation Need” — a designation from DNREC’s Delaware Wildlife Action Plan, the state’s conservation blueprint through 2035. Its 2025 update added 326 plants to that list, bringing it to 1,019 species across three priority tiers. If you want a bed that does conservation work rather than just looking like it does, that flag is the most useful thing in any catalog on this page.

On pesticides, they are unusually candid:

“Delaware Nature Society has made every effort to avoid neonicotinoids and other systemic pesticides being used on our plants. However, we cannot guarantee that every plant is pesticide-free.”

That is a more honest statement than most sellers manage. Neonicotinoids are systemic — they end up in pollen and nectar — so a “pollinator plant” grown with them can work against the point of planting it. Nobody selling plants at this scale can truthfully promise otherwise; saying so out loud is the tell of a trustworthy source.

The catch nobody mentions: cultivars vs. straight species

This is the one thing to understand before you show up with a wagon, and it is a real tension rather than a technicality.

The ★ list on this page is built from Mt. Cuba trial winners, and trial winners are overwhelmingly cultivarsSolidago rugosa ’Fireworks’, Phlox paniculata ’Jeana’, Schizachyrium ’Standing Ovation’. A native plant sale, reasonably enough, mostly sells straight species. So the specific cultivar this page recommends often will not be on the table.

Which is usually fine, and sometimes better. For most genera the straight species supports pollinators at least as well as the cultivar, costs less, and comes true from seed so you can divide and spread it for free. Buy the species and don’t feel you’ve compromised. The cultivar earns its premium when the trial found something specific — disease resistance, a habit that doesn’t flop, a longer bloom — and this page says so in the plant note when that’s the case.
One place the swap genuinely does not work: witch hazel. This plan uses Hamamelis × intermedia ’Jelena’ or ’Arnold Promise’ to fill the January–February gap, which is the hardest month on the whole calendar. DelNature carries the native Hamamelis virginiana — a fine shrub, but it blooms October–November. Substituting it leaves your worst month empty. Buy the hybrid from a nursery and get something else at the sale.

Substitutions that do work

From diffing the catalog against this page’s list, where the page wants a cultivar DelNature is unlikely to have, these are the straight species they carry instead:

  • Amsonia hubrichtiiA. tabernaemontana — coarser leaf, same blue, same reliability. Less of the famous gold fall color.
  • Hydrangea paniculata ’Limelight’ → H. arborescens — native, and the one Mt. Cuba trialled anyway.
  • Phlox subulata / P. stoloniferaP. divaricata — woodland phlox, better in part shade than either.
  • Solidago rugosa ’Fireworks’ → S. caesia or S. flexicaulis — both shade-tolerant, neither runs like the field goldenrods.
  • Ilex glabra ’Gem Box’ → I. verticillata or I. opaca — different plants, but both already on this page.
  • Coreopsis tinctoriaC. palustris — a late-season perennial rather than an annual, so it changes the plan slightly in your favor.
  • Viola × wittrockianaV. pedata, V. sororia orV. walteri — perennial natives instead of bedding pansies.
  • Verbena bonariensisV. hastata — and this one is an upgrade: bonariensis is South American and self-sows aggressively. V. hastata is native.

Already on the list, already available

Matching the catalog against this page on genus and species, 23 of these plants are sold by DelNature at $12–17 — meaning a large share of the herbaceous shopping list can come from one Saturday morning:

Agastache foeniculum · Aquilegia canadensis · Asclepias tuberosa · Carex pensylvanica · Cercis canadensis · Clethra alnifolia · Coreopsis verticillata · Cornus sericea · Hamamelis virginiana · Hibiscus moscheutos · Hydrangea arborescens · Ilex opaca · Ilex verticillata · Itea virginica · Liatris spicata · Mertensia virginica · Panicum virgatum · Penstemon digitalis · Phlox divaricata · Phlox paniculata · Rudbeckia fulgida · Schizachyrium scoparium · Tiarella cordifolia

How to work a plant sale. Go to the members preview if you can. Bring a wagon and a printed list sorted by bed, not by name. Buy the shrubs first — they sell out and they’re the ones doing the winter work. Accept species substitutions on perennials without agonizing. And check the catalog before you go: it lists most of what will be there, but availability moves right up to the morning of.

Availability figures here were produced by matching the Delaware Nature Society Spring 2026 catalog against this page’s plant list on genus and species. Fall sales weight toward woody plants and late-season perennials, so the fall list differs — treat this as evidence of what DelNature carries generally, not as a current inventory.

What to do, in order, starting now

If you’re reading this in mid-August, the timing is good — you’re about three weeks ahead of the best window of the entire year. If it’s later, pick up at whichever step matches the month; the cycle comes round again.

Late August — start here

Walk the site and identify what’s actually growing

This one step determines everything else. Photograph anything woody or vining and get IDs confirmed — the New Castle County Master Gardener helpline through UD Cooperative Extension will do this for free. Specifically look for tree-of-heaven, bittersweet, multiflora rose, knotweed, mugwort, bindweed, nutsedge and poison ivy. Then triage into the three zones. Mow everything short and rake the biomass off. Start collecting cardboard now — it takes weeks. Get a soil test through UD; it’s cheap and it tells you what you actually need to amend.

Also: treat Zone 3 now. July–September is the peak window when woody invasives are moving sugars down to their roots, which is exactly when systemic treatment works and cutting alone backfires.

September

Lay the beds. This is the highest-leverage month.

Sheet-mulch Zone 1: edge, soak, overlap 8–10 in, 4–6 in of mulch. Tarp Zone 2, black side up, weighted everywhere. And plant anything that’s already clean — September through October is the best planting season in Delaware. Soil is warm, air is cooling, rain returns, and roots establish with no heat stress. Perennials and shrubs planted now will be twice the plant next June that spring-planted ones will be.

Late September – October

Order and plant bulbs. Cheapest permanent color you will ever buy.

Plant at 2.5–3× the bulb’s height deep. Soak winter aconite and Anemone blanda tubers overnight first. Every bulb below is Rutgers A or B — deer will leave them alone, and most will still be flowering in twenty years.

A ~$60–80 order that carries February through May: 100 mixed early/mid/late daffodils · 100 Scilla siberica · 50 snowdrops · 50 winter aconite · 50 Crocus tommasinianus · 25 Iris reticulata ’Alida’ · 50 Muscari · 25 Camassia. Skip tulips.

Also in October: plant pansies and violas (they’ll flower into December and again from February), and put in the structural shrubs.

Late October – November

Fall-sow the hardy annuals — the free flower trick

Wait until the soil is genuinely cold (~50°F), then scatter larkspur, bachelor’s button, nigella, Shirley poppy, calendula and snapdragon right where you want them. They need cold to germinate properly, they’ll bloom weeks earlier and bigger than anything spring-sown, and most of them self-sow forever after. Surface-sow the poppies — do not cover them, they need light.

Then leave everything standing. Grasses, coneflower and rudbeckia seedheads, hydrangea heads, baptisia pods. That’s roughly 40% of your winter interest and it costs nothing.

December – January

Order seed. Start winter sowing.

Order in December–January, direct from the companies above, before good varieties sell out.

Then winter-sow in milk jugs — cut a gallon jug most of the way around, fill the bottom with potting mix, sow, tape it shut, leave the cap off, set it outside and forget it. Late December–January for perennials needing cold stratification (echinacea, rudbeckia, butterfly weed, liatris, columbine, penstemon, native grasses); late January–February for hardy annuals. It’s free, needs no lights or heat mats, and the stratification happens by itself. This is how you get $6 perennials for pennies.

February

The snow trick, and the winter cleanup

Scatter poppy and larkspur seed on top of late-season snow — the melt pulls it to exactly the right depth. Sounds like folklore; works reliably.

Late February: cut grasses back to 4–6 in, cut down last year’s perennial stems, cut old hellebore foliage off so the flowers show, and remove a third of the oldest stems from red-twig dogwood (only young wood colors well).

March

The honest checkpoint

Pull the Zone 2 tarps and look. If nutsedge, mugwort, bindweed or thistle are there — and they probably are — that zone gets another season under cover, not a planting. Re-tarp it and move on. Trying to plant into it anyway is how people lose a whole year’s work and a few hundred dollars of plants.

Zone 1: scrape back the mulch in a test spot. The cardboard should be soft or mostly gone.

April (after ~Apr 8–20)

Plant Zone 1

Plant through the mulch into actual soil — scrape aside, plant, pull back. Do not till.Perennials, especially summer- and fall-blooming ones, go in now. Direct-sow hardy annuals. Then start walking the beds every 2–3 weeks pulling any bindweed or nutsedge shoots before they re-establish.

May 1–10

Sunflowers go in

First sowing when soil hits 60°F. Row cover over the seedbed for the first ten days. Corral stakes driven now, not later. Then repeat every 2–3 weeks through early August.

~May 10 is also the safe date for tender annuals — zinnias, cosmos, cleome, four o’clocks, marigolds. Cover direct-sown seed with a thin layer of vermiculite or fine compost rather than garden soil, which crusts over and blocks emergence.

Late June – August

Too hot to plant. Water, deadhead, and enjoy it.

Shear catmint and salvia after their first flush for a second round. Sow one more wave of zinnias in early July for October color. Handpick Japanese beetles in the morning. Then in September the cycle starts again — and next year you’re planting into beds instead of fighting weeds.

A first-year shopping list

Buy as plants (~$525–875)

4 structural shrubs — these do all the winter work:
Hamamelis × intermedia ’Jelena’ or ’Arnold Promise’ (Jan–Feb) · Ilex verticillata ’Red Sprite’ plus one ’Jim Dandy’ male (Oct–Jan berries) · Cornus sericea ’Arctic Fire’ (Dec–Mar stems) · a Camellia ’Winter’s Star’ (Oct–Dec flowers).

Full-sun bed: Baptisia ’Screamin’ Yellow’ + ’Purple Smoke’ · Amsonia hubrichtii ·Nepeta ’Walker’s Low’ · Echinacea ’Pica Bella’ · Phlox ’Jeana’ · Coreopsis ’Zagreb’ ·Solidago ’Fireworks’ · aster ’Raydon’s Favorite’ · Ceratostigma along the front edge ·Schizachyrium ’Standing Ovation’ · Panicum ’Northwind’ · mum ’Sheffield Pink’.Every one is Rutgers A or B except the phlox.

Part-sun / shade bed: mixed Helleborus × hybridus · Sarcococca ·Carex pensylvanica · Heuchera ’Citronelle’ and ’Caramel’ · Epimedium ·Brunnera ’Jack Frost’ · Phlox stolonifera ’Fran’s Purple’ · Virginia bluebells · white wood aster.

Where that number comes from: 25 herbaceous plants at the Delaware Nature Society sale price of $12–17, plus 9 shrubs at $25–50. Buying the same list at garden-centre retail roughly doubles it. See Where to Buy for which of these they actually carry.

Buy as seed & bulbs (~$120–140)

Bulbs plus both kinds of seed. Materials are a separate line below — they’re the part most first-year budgets forget.

Bulbs, ~$60–80 (October) — the list in the timeline above. Twenty years of February-through-May color for less than the cost of four shrubs.

Flower seed, ~$30 — larkspur, bachelor’s button, nigella, Shirley poppy, calendula, borage, 2–3 colors of zinnia, Coreopsis tinctoria, Rudbeckia hirta, Aquilegia canadensis,Asclepias tuberosa.

Sunflower seed, ~$30 — 1 oz Mammoth Grey Stripe (the giants) · ½ oz Autumn Beauty (the wild color mix) · packets of Velvet Queen, Italian White, Moulin Rouge and Cherry Rose · optionally American Giant for the sturdiest tall one.

Materials and one-time kit (~$200–300)

Mulch/compost, a silage tarp, sandbags, row cover, deer netting, a soil thermometer.This is real money and it is easy to leave out of a plan — the tarp alone is what makes the staged approach work, and deer netting is not optional here.

Most of it is a one-time buy. The tarp, sandbags, row cover and thermometer carry over to year two and beyond; only mulch and compost recur. So this line shrinks to roughly $50–100 next year, while the plants line shrinks a lot more — the bulbs come back on their own and the annuals you fall-sowed self-seed for free.

What a first year actually costs, all in: ~$845–1,315.These figures include materials, not just plants — tarp, mulch, netting and tools are counted, because a budget that leaves them out is the reason people run short in April. Plants $525–875 · bulbs and seed $120–140 · materials $200–300. All plant pricing is at Delaware Nature Society sale rates; garden-centre retail roughly doubles the plants line. The low end of each range is the realistic figure if you buy at the sales, accept straight-species substitutions, and start with Zone 1 only.
Realistic first year: Zone 1 planted and blooming, bulbs in the ground working for the next two decades, one sunflower patch, and the annual seed you fall-sowed coming up free every year after. Zone 2 still under a tarp — and that’s the plan working, not the plan failing. Year two is when it starts to look like the pictures.

Things worth double-checking before you spend money

  • Camellia hardiness is the biggest gamble here. Buy an Ackerman "Winter" series or C. oleiferahybrid, rated to 6a — not a generic sasanqua. Site it out of morning sun and winter wind. Open flowers brown below ~25°F, though unopened buds keep coming.
  • Edgeworthia is rated zone 7–10 — genuinely marginal for you. Protected courtyard or east wall only, and expect to lose it in a −5°F winter.
  • Verify any single expensive plant’s deer rating directly at Rutgers before buying. Their list splits by species in places.
  • Confirm your exact zone by ZIP. Northern New Castle County straddles 7a and 7b; Mt. Cuba describes its own trial garden as 7a/6b, and it’s just a few miles from you. Plan to 7a to be safe.
  • Check the current Delaware invasive plants list before buying shrubs — the law changed in 2022 and several once-common landscape plants are now illegal to sell or propagate.