Plant Profile: Yellow Horned Poppy (Glaucium flavum)
I noticed, during my garden walk the other day, that my Yellow HornedPoppy had seedpods that were ready to pop. Now if you're into seedpods, as I am, those on the Horned Poppy are an absolute delight. First of all, they are long – really long, as in up to 12” (30 cm) and almost as narrow as the stem. When they first form and are green, it's hard to tell where the stem ends and the seedpod begins. However, it's very easy to tell when they're mature- the pods turn a dark brown and if they're ready, the pods will easily snap off the stem; if not, you can tug and twist with all your might and they won't budge. Opening the mature pods takes a simple twist and the seeds literally fall out. And there are so many of the tiny, little things! They run up and down the whole length of the pod – easy to figure out why this plant is a self-seeder.
Long, curvaceous seedpods!
I can't figure out why this plant is not more common in gardens. There is so much to love about it! The foliage itself makes it garden-worthy: the highly-dissected leaves are a bright silvery- blue and grow in a lush mound, providing visual interest all season. The pale yellow flowers on 24" stems are produced in abundance continually from July to September and as the flowers fade, those incredible seedpods begin to form. All in all, it's quite the conversation piece. On top of that, it's a pretty low-maintenance flower, growing best in poor soils, and it can handle variable growing conditions, including drought.
The Horned Poppy has a long history of cultivation. A native of the coasts of much of Europe and the Mediterranean, it was a cottage-garden favourite for hundreds of years and was grown extensively in England and Ireland. Gerard described it in the 16th C. Immigrants brought it with them to settle the New World and it flourished here, naturalizing along the eastern U.S. coast. Settlers did discover, 'though, that our harsh winters necessitated growing it as an annual rather than the short-lived perennial it is in Europe. An 1827 Ontario seed catalogue lists it as one of their offerings of annual flowers. Mine, however, have survived milder winters in our Zone 5b gardens.
To grow the Horned Poppy from seed, start it indoors in winter. The seed benefits from stratification (which means providing it with a cold spell to break dormancy), so after pressing the seed into moist, soil-less mix and lightly covering with mix, place a plastic baggy over the top and place it in the fridge for 6-8 weeks. Then remove the pot from the fridge and place it under lights. Or if you're lazy like me, simply place the pot of sown seeds outdoors in winter in a sheltered spot (without the baggy!) so it can experience the normal freeze-thaw cycles.