The previous owner planted several peonies on the side of the house. Usually the plants bloom very well, although the last 2 years have seen a steady decline in the amount of buds to only a handful on each plant. I do not think the sun patterns have changed that much. I have fertilized with manure and a general 10-10-10 slow release food. The plants are otherwise huge and healthy. Does anyone have any advice as to what I should be doing to get the plants to bloom well again. Thank-you.
Very few buds
The fact that your plants are huge and healthy is a strong clue. I take it that you are referring to the leaves.
You are taking very good care of your peonies - but I suspect a bit too much care. The manure is very good for them, and you should continue doing that, but the 10-10-10 fertilizer is feeding the leaves at the expense of the flowers. That is why they are so lush. Using no fertilizer would be good. Some advise (Old House Gardens) putting 10-10-10 around the outside of the plant, not on it.
From their site:
"Scratch a couple of tablespoons of balanced fertilizer (10-10-10 is ideal) into the soil around the plant, outside the ring of stems, as its leaves begin to unfurl."
But my guess is that you should stop using both manure and fertilizer, especially since manure acts as fertilizer. I personally use compost only.
If the plants were new a few years ago, sun patterns and the opportunity for roots to develop would matter because the plants are gradually using up what's stored. Are they only making a few buds, or do many look small and dried up? I put them to bed with a thin manure topping in the fall (also away from the plant) and fertilize lightly in the spring away from the plant as Donna mentions. I also sprinkle ashes periodically because they love the potash because of our sandy rocky soil. I think in your situation I'd look for fertilizer that is lower in nitrogen, the first number, to test the hypothesis next year. Soil PH, and soil quality, and whether they are competing with some other set of roots also matter.
I wonder if they could have settled and become too deep or perhaps the layer of manure have caused the eyes to be too deep. How thick of is the manure layer on the peonies?
I should say that sometimes I use compost or composed manure. Usually not more than 1' lightly applied.
kousa2012, The eyes emerge well and are as tall as other peonies
Rosemary K There should be more sun, since several trees on that side were cut down. All the other plants have not had any change.
I possibly could be over fertilizing in the spring: compost plus a general fertilizer (10-10-10) may just be too much. I think definitely I am going to get a soil test. I wonder if the ashes would help me.
Thank-you for all your input.
Even though the eyes emerge well they can still be too deep. I have found that my "helpers" have been known to toss extra soil around in the fall when doing cleanup, burying more of the plants than desired. Was astounded to find it happening, but my "helpers," well, I still have to say thank you and follow them around.
Ha ha! helpers are great to have but they do show us that there are different levels of plant knowledge.