My peonies have been tarped for 3-4 months now, and I can finally get a sneak peak into the results. Some of them have done a good amount of growth underneath the tarps even though the average outdoor temperatures has lingered only around 32F for the past 2 weeks. It has been colder than average for the entire winter however it looks like the ground will no longer freeze so it should be safe to expose them to the air.
Here are some of the tree peonies that have really sprouted fairly well. The Chinese tree peonies seem to sprout way sooner than the Rockii ones.
Some of these are set to flower right away.
There are green ones too.
On the flip side, some of them have been attacked by either voles shrews or some kind of rodent that chews off the cambium layer of the tree peony. This seems to happen almost only on the ones that are weaker and still on their herbaceous nurse root perhaps since they may have softer or younger wood, but I believe I may lose about 1% of my plants from this.
It is not that big of a problem when there are viable buds beneath the chewed section.
This sometimes causes them to rot. You can see the freshly chewed section. All I can do is add more soil and hope that having them uncovered can allow the rodents to take cover someplace else.
The one important thing is to have some cambium section still attached all the way down to the nurse root so that nutrients can be pumped up to the buds, and some of them look pretty bad.
For some reason, the ones that are on their own roots already just seem to be avoided even if almost the whole plant is exposed so perhaps the herbaceous nurse roots produce a better flavor. I guess that means not to avoid tarping grafted peonies right?
This is a worst case scenario where the entire thing gets devoured including nurse root which has only happened on a couple of them. There's no saving this especially since the tree peony section has already dried up quite a bit meaning I won't be able to quickly re-graft it. These rodents aren't very forgiving. I would like to use this blog to inform people not to tarp their grafted tree peonies if there are rodent problems because it allows them to have a warm place to feast on it.