Flowers

How to Grow Poppies: Planting, Spacing, Care & Bloom

Quick answer

Late fall or early spring direct sow (Cornell Shirley; USU breadseed). Optional transplants around last frost after 4–6 weeks indoors (USU) — prefer direct sow. Oriental poppy is a perennial with Low poison severity all parts (NC State). Legal for garden/seed; illegal to manufacture opium (USU).

Poppies at a glance

PlantStart indoors: 6–4 wk before last frost; Transplant: last frost
SunFull sun; well-drained fertile soil (USU/Cornell).
WaterWater sparingly after establishment (~1 in/week).
SpacingUSU breadseed: cover ≤⅛ inch (need light); rows 12–24 inches; thin to about 4–8 inches.
Days to harvestBreadseed pods ~80–90 days after planting (USU); prefer direct sow late fall/early spring
-7-6-5-4-3-2-1LF+1+2+3
■ Start indoors   ■ Plant out   ■ Harvest
Weeks relative to last frost (LF). Colored weeks show when our ZIP planner schedules each step.
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Updated

Safety: NC State poison severity Low for oriental poppy (Papaver orientale) — all parts poisonous including the juice. Genus Papaver: some species rich in alkaloids. USU: seed poppy can be grown legally for garden and seed production; it is illegal to manufacture opium from the poppies. This page is ornamental / culinary seed-head use only — do not harvest latex for opium. Keep seed/pod products from children/pets. Not medical advice. (NC State Papaver orientale; USU seed poppy)

Corn poppy flowers
Corn / Shirley-type poppy (Papaver rhoeas). Photo: Ввласенко, Wikimedia Commons, CC BY-SA 3.0 (resized).

Sourced from university extension guides. For dates where you live, use the ZIP planting planner.

Planting timing

USU breadseed: sow in late fall or very early spring (freeze/thaw aids germination). Optional transplants: grow 4–6 weeks, plant out around the last frost date — prefer direct sow (transplant poorly). Pods about 80–90 days after planting. (USU seed poppy) Cornell Shirley: scatter seed in late fall or early spring; indoor start 4 to 6 weeks before last frost is not recommended. (Cornell Shirley poppy) Oriental: perennial; propagate seed or root cuttings — not a spring frost-week annual sow model (NC). Planner optional: Start indoors last frost −6 to −4 then Transplant 0 (USU) — labeled prefer-direct. Late fall / early spring direct sow stays seasonal language.

Depth and spacing

USU breadseed: cover ≤⅛ inch (need light); rows 12–24 inches; thin to about 4–8 inches. Cornell Shirley: mix seed with sand; height about 2–3 ft. Oriental NC: height 2–3 ft; width 0.5–2 ft.

Sun, soil and water

Full sun; well-drained fertile soil (USU/Cornell). Water sparingly after establishment (~1 in/week). Avoid overhead wetness for mildew (USU).

Care

Direct sow preferred. Deadhead Shirley to prolong bloom / limit self-seeding (Cornell). Oriental: interplant fillers for the summer gap after die-back (NC). Culinary seed: harvest in dry weather when seeds rattle in pods (USU) — ornamental/culinary only.

Bloom

Breadseed: pods 80–90 days after planting (USU). Shirley: late spring–early summer (Cornell). Oriental: June–July then foliage dies down (NC).

Pests and diseases

USU: black bean aphids — insecticidal soap or strong water stream; slugs/snails on seedlings; downy/powdery mildew — spacing, avoid overhead irrigation. Cultural first.

Related: ZIP planner · organic pest control

Related: California poppy (Eschscholzia — separate page)

Frequently asked questions

When do I sow poppies?

Late fall or early spring direct sow (Cornell/USU). Optional transplants around last frost after 4–6 weeks indoors (USU) — prefer direct sow.

Is it legal to grow breadseed poppies?

USU: legal for garden/seed production; illegal to manufacture opium. Follow current law; this page is ornamental/culinary seed only.

California poppy?

Separate page — Eschscholzia, not Papaver.

Sources