Hello, I planted this Tree Peony 'Koukamon' in my daughter's garden in Salt Lake City about 3 years ago. Each year it has shown signs of chlorosis, but we have been able to correct it with amendments and iron chelates. Her soil is awful clay with all sorts of contractor debris thrown in. We did amend each year with compost but it's obviously not enough!
This year, it has grown, is blooming and the whole plant is sickly yellow. I guess I really need to move the poor thing - do I have to wait until it goes dormant in winter, or can I carefully move it after it finishes blooming? The sticky clay soil allows you to get a really good intact root ball, usually.
I would move it. Sounds like it's stilll getting too much water; clay is sometimes so unforgiving. I'd worry it would die completely over the growing season. You sound like you know what you're doing but if it was mine if I left it in that spot I'd dig a good size hole, take a big rootball and add rock to bottom for drainage. Then I'd amend the soil with quite a bit of sand, clay retains too much moisture. Compost is excelllent but might not provide the "air" it needs.
Probably others would disagree heartily. I've moved 2 gas plants successfully and "they" tell you never to do that, so am an unorthodox renegade. But I've lost tree peonies in the past and hate that; too expensive. I'd move it, this is one of two times during the year plants don't mind the interruption, most don't know what hit 'em.
If this is a cool time for spring like it is here, I'd wait for a predicted cloudy, rainy period to do the move. Or since sun is the killer of moved plants, provide an artificial barrier between sun and plant for an extended period (I use buckets and move with sun). I might also try cutting off some wood if it continues to go downhill, but that would change the shape and that would be a shame.
It also makes a difference what the summer temperatures are there. In a more northern climate with cooler summers, plants can do OK when transplanted this time of year (or even potentially getting farther into summer) but in a climate with hotter summers it can be very challenging to transplant things this time of year since it'll be hot very soon if it's not already. Since it's survived 3 yrs in that location it probably isn't in imminent danger of death if you leave it until the fall to move it, and it'll be less stressful then since it won't have to deal with hot sun while it's trying to get established. I have no idea what summers are like in Utah, but I know in much of the inland west things tend to be pretty hot & dry so thought I would mention that.
Yes, it is hot and dry in summer, but not really killer heat until mid-July. In fact, June can be somewhat rainy there.
But, as you point out it's not in imminent danger of croaking before it goes dormant in the fall, so I think what I'll do is treat it with chelates again, prepare the new spot on my upcoming visit, and plan to move it when I go back for Christmas. Let's just hope the ground isn't frozen by then!
For looking such a terrible color, the plant is amazingly perky, I think. It has grown substantially since I last saw it in October, and has 4 blooms, where it only had 2 last spring! Guess it's getting enough food from the leaves to "Live Long, if not Prosper".
I have had some success by planting chlorotic plants which can't change in a 20 gallon or more pot sunk in the ground up to the pot lip with an ideal mixture in the pot. The good soil mix is isolated from the rest of the soil and will stay that way for years. you must water more in drought conditions.
Thanks, all. I may consider sinking a pot, although digging a big enough hole in the terrible hard clay is a huge job. The color is a bit 'off' in that picture, it is really a rich dark burgundy red, not purple. Hoping it will still have a flower next week when I arrive - I bought and planted it, but have never seen it bloom in person! If I do, I'll post another picture.