Grow horned poppy in full sun, in lean soil that drains. Horned poppy is Glaucium flavum, also called yellow horned poppy. It is not a true poppy.
Give it full sun, lean soil that drains, and little extra water
| Factor | Recommended | Avoid |
|---|---|---|
| Sun | Full sun all day | Do not site it in shade |
| Soil | Lean sandy or gravelly soil that drains | Do not leave it in heavy wet clay |
| Water | Water until the plants are up; then water little | Do not leave the roots wet in winter |
| Feed | None | Do not keep the soil rich |
| Drought | Tolerates dry spells once the plants are up | Do not skip water while seedlings are still small |
Horned poppy wants a hot, draining spot and poor soil. Extra fertilizer makes soft growth that dies when the bed stays wet in winter. Water until the plants are up, then ease off. Soggy soil around the taproot in winter is the primary cause of root rot. [1] [2] yellow horned poppy wants that same lean drain.
Does horned poppy need full sun?
Yes. Give it a full day of light. Shade makes a weak rosette and few flowers.
How often should I water horned poppy?
Keep the surface moist until seedlings show. After that, water only in a long dry spell. Do not leave the roots wet in winter.
Sow in place in fall or early spring, and do not move the taproot
Sow where the plants will bloom. A moved taproot usually fails, so a tray start that you later transplant often dies. Sow in fall, or in earliest spring as soon as the soil can be worked. [3]
- Clear a patch of bare ground that drains. Pull weeds so the tiny seedlings are not lost.
- Scatter the seed on the surface. Press it in, or cover it with a thin layer of sand. Do not bury it deep.
- Keep the surface moist until seedlings show. Germination can take two to four weeks, and it is sometimes slower.
- Thin to about 12 to 18 inches. Do not lift and move a taproot. If you started a small plug, plant the whole plug while it is still young.
When should I sow horned poppy seed?
In fall, or in earliest spring after frost. Sow on the bed where the plants will bloom.
Can I transplant horned poppy?
Avoid it. The taproot usually fails after a move. Sow in place, or plant a very small plug without breaking the roots.
Not a true poppy — California poppy is Eschscholzia
Horned poppy is Glaucium. California poppy is Eschscholzia — see How to Grow California Poppy. Oriental, Iceland, breadseed, and corn poppies are Papaver — see How to Grow Poppies. Wood poppy, also sold as yellow wood poppy, is Stylophorum, a moist-woods plant, not this gravel poppy. Japanese wood poppy is Glaucidium, a different genus. A shop tag that only says poppy is not enough. The long, curved seed capsule is the horn. Read the Latin before you buy. [4]
Is horned poppy a true poppy?
No. Horned poppy is Glaucium flavum. True poppies are Papaver. California poppy is Eschscholzia.
If the bed stays wet in winter, sow the next patch on gravel or sand that drains — do not add more water.
FAQ
Can I grow horned poppy in a pot?
A draining pot can hold a few plants on a patio, but the taproot wants ground. Use a lean mix, and do not keep it wet in winter.
Should I deadhead horned poppy?
Pick off spent flowers if you want more bloom and fewer seedlings. Leave some of the long capsules if you want the patch to reseed.
Is blackspot hornpoppy the same plant?
Blackspot hornpoppy is Glaucium corniculatum, a red horned poppy with a dark spot at the petal base. Give it the same sun and drain, and sow it in place. It is not rose black-spot disease.
Is grand-flowered horned poppy a different species?
Grand-flowered horned poppy is Glaucium grandiflorum, a larger orange cup. Sow it the same way, in full sun on ground that drains.
Are horned poppies poisonous?
Do not eat any part of the plant. The sap and roots are poisonous if swallowed. Keep pets from chewing the leaves.
Can I sow yellow horned poppy on a beach?
Massachusetts lists yellow horned poppy as a prohibited plant. Do not sow it on a beach or wild coastal ground there. In a gravel garden, deadhead if you do not want volunteers.
Is horned poppy the same as wood poppy?
No. Wood poppy is Stylophorum, a moist-woods plant. Japanese wood poppy is Glaucidium, not Glaucium. Horned poppy wants full sun and lean soil that drains.
Recommended plants
References
- [1] San Marcos Growers -
https://www.smgrowers.com/products/plants/plantdisplay.asp?plant_id=3728 - [2] Plants For A Future -
https://pfaf.org/user/Plant.aspx?LatinName=Glaucium+flavum - [3] Select Seeds -
https://www.selectseeds.com/products/horned-poppy-burnt-orange-seeds - [4] Native Plant Trust -
https://gobotany.nativeplanttrust.org/species/glaucium/flavum/
More first-season notes by plant are gathered in How to Grow Guides.
Updated: Reviewed by Bosquelle Editors