Tree Peony Paeonia Ostii
Not sure if your tree peony is happy? Does it seem to be growing leaves each year, but no flowers? Does it still just have 1 or 2 stems? If so, your tree peony might not be very happy. There's a saying that says tree peonies don't like to be moved, which is probably true for very mature and established tree peonies that are quite large shrubs. However if your tree peony isn't happy, moving it is probably a good idea. If you can't tell if your tree peony is happy, here's a little secret to help you figure it out. Check out the base of your tree peony. Do you see any new growth popping up from the base of it? Not just leaves - but new stems!
Tree Peony 'Shimadaijin'
These new stems won't be woody. They will be fleshy and coming up from the dirt/mulch/base of the plant. The new stems will eventually become woody (by the next year), but when they first come up, they look very herbaceous. Now the appearance and the coloring of these new stems may look different on each tree peony variety. Some new stems may be red, some may be purple, some may be green, and many may exhibit a combination of these colors. The important thing to note is, do you have new stems coming up from the base of the tree peony plant? If you don't and you haven't for more than 2-3 years, then your tree peony is not happy. It is not becoming established in the area you've planted it. Now part of it could be the planting location, but there are many reasons your tree peony might not be happy.
Tree Peony 'Sahohime'
If your tree peony isn't happy after 2-3 years (and it is still alive), I would recommend moving it. If it does not become established, it will eventually die. Where to move your tree peony? Examine the area it's planted in now. Does it receive enough sun? Does it have even moisture throughout the year? Is it planted deeply enough? The biggest keys to making sure your tree peony will grow and establish itself in the landscape are: sun, moisture, and stem access to soil. Let's talk about each of these 3 areas.
Tree Peony 'Yao Huang'
1. Sun - Tree Peonies like a sunny location in the garden, they can take a small amount of shade, but ideally you don't want too much competition from large trees. So sunnier is better. Partially shaded or sheltered by a structure for half the day, like the side of a house, a pergola, a fence, etc. may be beneficial.
2. Moisture - Tree peonies like even moisture, but not too much moisture. The soil should be well draining and rich in nutrients. Planting near a structure also helps conserve soil moisture.
3. Stem Access to Soil - This is most important if you are purchasing a named tree peony variety. (If you are growing tree peonies from seed, you can ignore this one.) Most tree peonies sold today are grafted. (Maybe one day they'll be clones growing on their own roots!) Grafted means you cut a stem from an existing tree peony and merge it with the root of a different peony (usually an herbaceous peony). Since most tree peonies sold commercially are grafted, it is really important that a large part of the stem section of the tree peony be planted under the soil. This will give the tree peony the opportunity to grow its own roots - which is really important for helping the tree peony become established.
Tree Peony 'Angel Emily'
So if you do decide your tree peony isn't happy and decide to move your tree peony, make sure to take into account those three things when replanting it. Try to give your tree peony "the best spot in the garden" not some off to the side, right next to a tree trunk kind of spot. Also it wouldn't hurt to mix in a cup of organic fertilizer into the soil while you are replanting it - and remember - plant it deep! Way deeper than you think. Most people probably try to plant their tree peony with the "roots" underground and the "stem" above ground. I would say you really want to plant it with about half of the stem underground (about 3-4 inches). You really want some of those "buds" on your tree peony stem to be underground and some to be above ground.
Tree Peony 'Angel Emily'
Once you've gotten your tree peony "happy", it will go from just a couple stems to more stems than you can count - like these last 2 photos of Tree Peony 'Angel Emily', which I highly recommend. Tree Peony 'Angel Emily' is an American Peony Society Gold Medal Winner and a
Southern Peony Best Performer! :-)