2012 Questions - Itoh Peony Planting Depth

Itoh Peony 'Barztella'

I received this question from Karen in Zone 6:
"How deep do you plant your Itoh peonies?"

Itoh Peonies are intersectional peonies. Toichi Itoh is credited with being the first hybridizer to successfully cross a tree peony with an herbaceous peony, resulting in an intersectional peony. Since these peonies are a cross between tree peonies with woody stems and herbaceous peonies with herbaceous stems, the stems of intersectional peonies are semi-woody. These stems can be left on the plant and cut back to the lowest bud or be cut off completely. This picture is of intersectional Peony 'Bartzella' whose stems were cut back to above the lowest bud. I have drawn a line on the picture to show the proper planting depth for this type of peony. The stems (above the red line) face up towards the sun, and the roots (below the red line) should be planted below ground. So the proper planting depth for intersectional (Itoh) peonies is right at this joint between the stems and the root. If your intersectional peony does not have any above ground stems, then I would recommend planting the roots below the soil with the eyes or buds facing up towards the sun. The eyes or buds should be even with the soil level or just below the surface of the soil.

2012 Intersectional Peony Garden Dead Foliage

I went out to water the newly transplanted peonies in my intersectional peony garden today, and the ones that were moved from partial shade to full sun were toast. The new ones that I'd gotten on Ebay and planted out at the beginning of summer are the only ones that still have green foliage. The foliage on the ones that were planted in shade was a lighter shade of green (presumably because those plants were used to their partially shady conditions), but it became decidedly droopy, brown, and crispy. So I decided to go ahead and clean off all of the foliage from the older intersectional peonies that were transplanted from the shade. Now as you can see the garden is mostly just sticks, save the four very small, new intersectional peonies. I'm thinking the foliage on all of these intersectional peonies will be a nice dark green color when they leaf out in the spring. I can't wait!
Intersectional Peony Garden with Dead Foliage


Intersectional Peony Garden with Trimmed Foliage

2012 How to Plant an Intersectional Peony

Intersectional Peonies
Intersectional Peonies should be planted similar to Herbaceous Peonies, except a bit more care should be taken to make sure the root is facing the proper direction. This is important for herbaceous peonies as well, but more so with intersectional, and even more so with tree peonies.
Dig Hole for Intersectional Peony
The first step and perhaps the most important step in planting a peony is preparing the soil. I usually dig at least a 3 foot round hole for each root, spading the soil with my shovel to make sure the dirt is nice and loose. After the hole is dug and the soil has been loosened, I add some organic fertilizer and lime (dolomitic limestone) to the soil in the hole and mix it in. The fertilizer is used to add nutrients to the soil and the lime is used to adjust the PH of the soil. In my area, most soils are acidic, and peonies prefer a more neutral to very slightly acidic soil, around a PH of 6.0 to 7.0.
Put Intersectional Peony Root in Planting Hole
Next take a look at the peony root and make a small hole in the middle of your 3 foot round hole that will accommodate the size of the peony root. Intersectional peonies are hybrids of tree peonies and herbaceous peonies, and they exhibit some characteristics of both. The intersectional peony roots usually have a definite delineation between the roots and the stem. The stem usually has pink buds on it, from which the new shoots and foliage will begin to emerge. So make sure to put the roots into the soil and put the stems/buds pointing up towards the sky. In my southern climate the point where the roots meets the stem can be planted even with the soil, so that the roots are below the soil and the stems/buds are above the soil.
Cover Intersectional Peony Roots with Soil
Once the peony root has been planted, I cover the planting hole with a 1-2 inch layer of mulch. You don't want to put too much mulch on peonies in this climate. Otherwise the roots may not get enough chilling hours needed for blooming. They do however need enough mulch to retain moisture (It does get really hot here!) and prevent weed growth. After the peony has been mulched, I water the newly planted peony root. You can water your root before or after you mulch it. I just like to water mine afterwards because it seems like the soils stays in place a little better with the mulch already on top.
Mulch Intersectional Peony

2012 Peony Experiments - Intersectional Divisions

I divided a huge Peony 'Bartzella' this week with 24 stems. I ended up with 10 divisions. Four of the divisions have large root systems, and I know they will grow fine. However 6 of them had little to no root left on them. Since Peony 'Bartzella' DNA seems to be quite valuable these days, and I am not currently in the business of cloning :), I thought I'd plant them out to see if they'd survive, grow, and thrive. Some of them have only a stem and a bud on them. So those I planted a little deeper hoping for an adventitious root. I know some peonies are known to create adventitious buds. So I'll be curious to see if these are able to develop adventitious roots. :) I planted these out in my new peony seedling test bed which I guess is now just my peony test bed. I also had a little helper that sprinkled a bit of water on them. :)

Peony 'Bartzella' Division with Small Roots	Peony 'Bartzella' Division with Small Roots Planted
Peony 'Bartzella' Division with Tiny Roots	Peony 'Bartzella' Division with Tiny Roots Planted
Peony 'Bartzella' Division with No Roots	Peony 'Bartzella' Division with No Roots Planted

Peony Helper

2012 Intersectional Peony Garden Planting

Wow! Planting the intersectional peonies in their new garden bed was a dream. The new soil was so soft and even the earth below was easy to work with considering how much rain we've had lately. At first I couldn't decide on the layout. I wanted the layout to be different than my other peony beds. I finally decided on concentric circles with Peony 'Bartzella' in the center.
Intersectional Peony Bed Layout
I guess I will be enlarging this bed very soon. I pretty much filled it up. I dug up or divided 6 intersectional peonies that I already had elsewhere in my garden - shadier spots, which is why they needed a new home! I've had them for years with little to no bloom. I'm hoping with the move they will be happier and produce lots more blossoms! Those peonies were Peony 'Copper Kettle', Peony 'Cora Louise', Peony 'First Arrival', Peony 'Hillary', Peony 'Julia Rose', and Peony 'Morning Lilac'. I also added my four intersectional Ebay peonies Peony 'Canary Brilliants', Peony 'Lemon Dream', Peony 'Old Rose Dandy', and Peony 'Scarlet Heaven'. Then I planted two new intersectional peony roots that arrived last week Peony 'Garden Treasure' and Peony 'Sonoma Amethyst'. I can't wait to see how this intersectional peony garden develops over time!
Intersectional Peony Bed Planting