Most flower growers prefer to plant peony tubers in the fall. But in Oregon, you can also put them into the ground in spring. As you may know, the genus Paeonia contains dozens of species that can thrive in the colder parts of Oregon. When to plant peonies in Oregon?
Quick Answer
In Oregon USDA zones 5-7, plant peonies in late winter or September and covering the ground with mulch is highly recommendable.
And if you start planting the hybrids, soon you will run out of space. But the most important takeaway is to pick a time that is most beneficial to your variety.
Once you select a spot that gets full sun for a minimum of six to eight hours per day, you had better plant peony tubers in September.
September is the best month to dig, divide, and replant peonies. But you can also plant new herbaceous peonies in February or as soon as the soil is workable.
Before You Plant Peonies In Your Backyard
Peonies are one of the easiest flowers to grow that you can put in your garden if you live in Oregon. Of course, you need to pick the right time to put them in the ground first. And it all starts by understanding the difference between the three main types of peonies.
- Herbaceous peonies die back to the ground every fall and emerge again the following spring.
- Tree peonies create a more woody stem above ground. And although they lose their leaves in the fall, they leaf out on the same old branches in the spring.
- Itoh peonies are a hybrid cross between an herbaceous and a tree peony. In brief, they are prolific bloomers, and there are tons of colors available for you to choose from.
When To Plant Peonies In Oregon USDA Zones 5 And 7
In Oregon USDA zones 5-7, planting them in late winter or September and covering the ground with mulch is highly recommendable. Additionally, put a grid stake or a peony support ring to mark the spot.
Do not plant peony trees after mid-May, though. Unlike Itoh peonies, peony trees need cold temperatures to establish. You might plant most herbaceous and Itoh species untill May 15 and pull it off. But it will not go well for the more cold-hardy varieties.
Can I Plant A Peony If I Live In Oregon USDA Zone 8 Or 9?
Usually, most peonies do not deal with the mild winter very well. So, your best option to grow beautiful peonies in zone 8 is to pick a variety that tolerates it like:
- Delavay’s tree peony (Paeonia delavayi)
- Chinese Moutan peony (Paeonia suffruticosa)
- Tibetan peony, also known as Ludlow’s tree peony (Paeonia lutea var. ludlowii)
Sadly, growing herbaceous and Itoh peonies in zones 8 and 9 is almost impossible. Especially in zone 9. The lack of cold makes it hard for the plant to establish and survive during the rainy seasons—rain destroys the flowers.
On the other hand, planting peony trees may give you a rewarding surprise. But expect this task to be a difficult one. You might want to start your peonies right in the ground and not transplant them because this flowering plant does not like to change location.
Above all, if your experiments fail, remove the old soil before planting a new species in the same spot: peonies are picky about soil quality and always need fresh, humus-rich soil every time you plant them.
4 Tips To Grow Peonies In Oregon
- Bare-root peonies and tubers only need to sit two inches below the soil surface. Otherwise, planting them too deep will delay bloom time or cause them not to bloom at all.
- Give your peony tubers two months to get established before the first big frost. Why? Because the tubers need to spread their roots before the winter sets in. Extreme cold is necessary for the tubers to acclimatize, but it will do more hurt than good if the tubers have too little time to prepare.
- If you put herbaceous peonies in USDA zones 7 and 8, deadhead your peonies when the blooms wither. In this way, the plant will not send energy into creating seeds. On the contrary, it will use that energy to build its root system even more, which will help the plant establish even more and create more flowers for the following years.
- When picking peonies at a garden center, make sure the leaves are super green. Do not pick yellowing or dried-out plants. If you spot brown leaves, they might have Cladosporium spores on their leaves, which are wind-dispersed. Do not touch any of the surrounding peonies!
Related Article: Why Do Peonies Not Bloom?