Peonies are slow growing, but yes, you can start them from seed. Photo: palmitersgardennursery.com & http://www.ebay.ie, montage: laidbackgardener.blog.
Did you know that, if you’re a very patient gardener, you can grow peonies from seed? Expect to wait many years before the plant fills in and really starts to show off, but it can be done.
Do note that the peonies you grow from seed are unlikely to be identical to the mother plant. It was probably a hybrid, containing a mix of genes, and this will give a mix of results in its babies. So, expect the unexpected!
Here’s what to do:
From Bloom to Seed
Start by doing nothing: do not deadhead your peonies after they finish blooming. (That’s easy enough for me: I never deadhead peonies!) Seed pods will start to form at the tip of the stem where the flower was. Some varieties readily produce seed pods, others only very reluctantly or not at all.
At the end of summer or in early fall, when the seed pod starts to open, harvest the seeds. Don’t dry them out! That can slow down this already very slow process even further!
From here on, there are two possibilities: you can sow the seeds outdoors, the way Mother Nature intended, or indoors, where you have more control. The important thing to understand is that peony seeds need to be in contact with moist soil over a warm period (fall or the equivalent, where the soil is still warm) followed by a long cold period (winter) in order to complete their germination. So, warm and moist, then cold and moist.
Sow the large seeds in a prepared bed about 2 inches (5 cm) apart and 1 inch (2.5 cm) deep, preferably in full sun. Water a first time, then keep the soil reasonably moist in case of drought.
When winter approaches, it’s best to mulch the seed bed with your favorite mulch (I just use chopped leaves) to protect from the damaging effect of alternating freezing and thawing.
During the summer that follows, keep evenly moist. Mulching the seed bed will help with that.
Most seeds will sprout the following spring, but some (tree peonies, notably) may take a second year, although they may be producing roots sight unseen under the soil. So, if nothing seems to be happening, just keep the spot evenly moist and wait patiently.
In fact, you may find stray seedlings appearing in the seed-bed years after you’ve moved the others. That’s just the way things are with peonies!
Plant the freshly harvested seeds in a 6-inch (15 cm) pot of moist soil, again at about 1 inch (2.5 cm) deep, spacing them about 2 inches (5 cm) apart. Place the pot inside a plastic food storage bag and seal.
If possible, place in a very warm spot (about 80˚C/27˚C, maybe on top of a plant light). Room temperatures will do, but might slow down rooting. Keep the pot warm and moist for about 3 months, then move it to your refrigerator for another 3 to 4 months. By then, it will be spring and you can move the pots to a bright spot at room temperature. When green growth appears, remove the plastic bag and move the pot into full sun.
If nothing germinates, don’t give up. Keep the pot inside its sealed bag, warm and slightly moist, then, after 3 or 4 months, refrigerate again for 3 to 4 months before putting it back in warm conditions. This second warm/cold treatment ought to snap even the most recalcitrant seeds out of their lethargy!
In late spring, when there is no more risk of frost, carefully plant the sprouted seedlings in a sunny spot in the garden in fertile, well-drained soil. Don’t put them in their final place just yet: grow them in a plant nursery for a few more years.
In Both Cases
Keep seedlings at least slightly moist at all times. If you live in a cold climate, mulch the young plants in the fall, just in case.
Peony seedlings grow slowly. Some may produce a first flower are early as the 3rd year, but more likely in year 4 or 5. At this point, you can carefully move them to a permanent home. This is best done in late summer or early fall.
By the time they’re 7 or 8 years old, most will be performing like pros, possibly out-blooming the other peonies in your garden. And they’ll be your peonies! You can even name them, as each will be a different cultivar with its own particularly traits. Who knows? One of your seedlings might turn out to be an award-winner: stranger things have happened!
Peonies from seed: slow by steady wins the race!