Have you tried taking the flower heads and shaking the seeds where you want them to grow next year? I did that and have three new plants. If the one poppy hasn't produced more in 7 years it sounds like it isn't in an ideal situation. Wood poppies thrive in moist conditions. If consistenly moist, they can take quite a bit of sun, if conditions are drier then they need less sun. I am fairly certain that wood poppies only bloom in the spring and can't be encouraged to bloom later in the season.

Thanks. I'll try shaking seeds. The plant is in full sun now -- used to be partial shade, but lost a big maple. I do get a few blooms through the summer and quite a few more in the fall, after the weather cools.

The seed pods form after the flower fades and are green, fuzzy, enlongated globules that hang on a long petiole below the leaves. When they turn from green to a straw or tan color, they are about ready to open. After a few days you will begin to see tiny vertical cracks forming in the pod. Collect them and place in a brown paper bag or spread them out on a piece of paper and they will continue to open.
The seed are black and very tiny, one pod can have dozens of seed, very large ones may have well over a hundred. Mix with very fine sand and sow immediately. Germination rate declines very rapidly with age. The roots are shallow and they are easily transplanted by lifting a 3 inch thick rootball, six to eight inches in diameter. I have placed those on untilled soil and as long as they obtain occasional moisture, they continue to grow. I started with a single plant from our local Native Plant Botanical Garden and now have hundreds and have given away twice that number. In my Zone, there is a flush of blooms in Spring(they just finished and seed pods have formed), but they continue to produce a few blooms until frost.
Caution! Some gardeners are allergic to the yellow sap that flows from cut or broken stems and it is difficult to remove the stain from your skin. If you have deer, they will pass lots of plants to feast upon the Celandine or Wood Poppy!
Rb

Thanks for the helpful details! I love this plant and am eager to get it going in my more woodsy areas.

Hmmmmm.......just when I was thinking I would like to collect the seeds on my one plant in my fenced-in back yard, and put them in the woods, I read the deer-part. If something is yummy to deer, it doesn't stand much of a chance here. Will they eat all my efforts?

I just divided mine on Saturday during a light rain. Have tons of seedlings and have given lots away over the years but a relative wanted a BIG one. It was kind of getting a bit thuggish where it was anyway.

What looked like two large clumps were coming up very close together so I just guessed and aimed the spade.... turns out both clumps were coming up from the same enormous yellow root which I had inelegantly sliced in two. I can personally attest to the ability of their resin to stain skin (looking at hands now) quite yellow.

Both patients seem to have thus far suffered no ill effect from their maltreatment, one remains where it was the other was moved several miles away (to a much grander garden). Keeping them watered but they both look quite perky. Probably would not have done it if I had just the one as you do.

BTW I find they continue to bloom throughout the summer 'til frost if kept well watered.

My experience is that deer are very fond of celandine (pass the Thousand Island please!). But also incredibly prolific self seeders. If you have one, you have dozens. They grow in partial shade, moist rich soil, bloom from mid April until late fall in NE Pennsylania with continual reseeding throughout the summer.

I agree that there can be sporadic bloom well after spring if they are happy.

Springcherry

The deer seem to pass mine by on their way to the azaleas. My native azaleas have all become trees as a way of defending themselves from foraging deer. I have some as tall as 12'.

My uncle just sent me some clumps of them.
Will these make it in a pot for a year? Or do they really need to be in the ground?

I really don't want them to die on me.
They have to go in the front yard, so the puppy won't get poisoned out back.

Regular soil will work I suppose, kept moist and in part shade. I can mix some potting soil with regular dirt, if it's to fertile.

my poppy keeps giving out baby plants in a mostly shady bed. i've even dug up the baby plants and given them to my daughter. we have deer but they don't eat them probably because they're close to house.