It's hard to believe that a plant as lovely as a peony requires so little maintenance.
If planted properly, given the right conditions and provided a minimal amount of annual maintenance, your peony plant will provide you unparalleled beauty for 50 years or even more.
To ensure your peony plantings are successful, we've summarized the key aspects of peony care below.
Monitor for plant disease and remove any affected part of the plant.
Fungus (excluding Powdery Mildew)
In particularly wet years, it's common to have fungus - such as botrytis - affect your peony plants. When you see this happening considering removing areas of the plant that are most impacted.
We have noticed that plants affected by late spring frost and heavy spring winds are more susceptible to fungus in general. Our guess is that the frost and/or heavy wind weakens those plants, which in turn makes them an easier candidate for disease.
If you are noticing this, you can plant windbreaks around your plants. You may also choose to move them to a more sheltered location.
Powdery Mildew (PM)
Our customers frequently complain of powdery mildew on their plants. We are lucky in that our PM issues have been very limited on our farm.
However, when we gardened in Brooklyn, PM was literally everywhere. Here are some tricks we found to help minimize it:
1) Keep you plants well watered.
PM will also come on during a dry spell. If the weather turns dry, consider giving your plant a good soak. This may prevent - or at least slow - it's development
2) A small amount on your plant does very little damage.
We only saw PM start to cause bigger issues with the plant, if the PM truly coated the majority of the plant. Short of that, it will be unsightly but probably not terribly harmful
If a plant got truly coated, and it was later in the growing season, we typically cut it back.
3) PM is more likely to develop if there’s too little or too much wind. (I know - a gardener just can’t win, right?).
If there’s no circulation around the plant, it encourages PM
Conversely, if you’re in a wind corridor and - upwind of that wind corridor there is a source of PM - your plants will be more affected.
If you can’t eliminate the source of the PM, then consider sheltering the plant from the wind or moving it to a new spot
4) Some varieties are more prone to PM.
We noticed that our tree peonies and itohs got substantially less PM than our herbaceous peonies. Within the herbaceous category, we saw the most susceptibility on the lactifloras.
f you have some lactifloras that are perpetually plagued with PM, then you might consider not growing those varieties and instead focusing on varieties that fare better in your garden.
Remove all plant foliage in the fall when the plant goes dormant.
Discard or burn the foliage. Do not add it to your compost pile.
Peony foliage that is not removed can harbor fungus. This removal step is critical if you want to prevent disease in your garden the following year.
For herbaceous and itohs, you can remove the foliage by simply cutting the whole plant back, leaving 2-4 inches of stem to help you remember the exact plant location
For tree peonies, do not cut back. Simply remove the leaves and discard or burn.
Consider applying compost annually.
Peonies are not a hungry plant and can do well in soil that isn’t very rich.
However, we’ve had good success with applying a thin layer (1-2”) of composted material every year.
When applying compost, please be aware to not apply compost over the peony’s “crown” (the area from which the peony stems grow). Applying compost to the crown could eventually cause the planting depth to be too deep. This can affect flowering.
Simply apply the compost up to the drip line of the plant and no further.
When Needed Or wanted, Divide your Peony and make more plants!
There can be many reasons to divide a peony some include:
1) The peony has outgrown its space.
2) You love the variety and want to make more plants for elsewhere in your garden.
3) The peony has become sluggish or developed disease and you want to re-invigorate it.
In these cases, it’s a great idea to divide your peony. Here’s some guidance on how to do it!
The planting video referred to in the above Division Video can be found on the Planting Your Peony page.