Spring Fertilization of Peonies
Once the snow is melted, the peonies are beginning to wake up. We generally leave a few inches of natural mulch, i.e. leaf litter around our peonies for the winter. With our herbaceous and intersectional peonies (as shown above) we leave 2-3"of stem in the fall so its easy to find them in the spring even when they are covered with mulch and the eyes are just beginning to peek through.
We feel its best practice to remove any mulch from the base of the peony. With herbaceous and intersectional peonies (as shown above), removing the mulch ensures that new growth will not be inhibited. With tree peonies, its also a good idea to remove the mulch from around the stems, as this can trap excessive moisture and lead to fungal issues.
A blend of fertilizers and soil amendments is recommended for successful peony growing.
At Cricket Hill Garden we use these three soil amendments in combination around all of our peonies in the spring. We use the lime to raise the pH of the soil. Our natural pH is around 5.5, but with regular application of lime we have succeeded in raising it to around 6.5, a level for good peony growth.
NOTE: If you have applied lime in the last year, it is not necessary to do so again now. Just as peonies resent a low pH soil, they will also struggle in soils with excessively high pH. If you are unsure of your soil's pH its best to have a soil test done to understand your baseline. Most state universities or state agricultural experiment stations preform this test for a nominal fee. See for example, the UCONN Soil Lab.
Azomite, a crushed volcanic rock powder, contains 70 different minerals and trace elements. These micro-nutrients help facilitate healthy plant growth. We have found to be an excellent supplement for our peonies, other perennials as well as in the vegetable garden.
Finally, we add a handful of low nitrogen fertilizer to the drip line of the peonies. We like to use Rose & Flower (4-8-4) Organic Fertilizer. It's blend of Natural Sulfate of Potash, Phosphate Rock, Vegetable Protein Meals, Animal Protein Meals, and Natural Nitrate of Soda. In the past we have recommended North Country Organics Pro-Gro (5-3-4), but are no longer able to stock this fertilizer.
Mixture of lime, azomite and fertilizer is spread around the the drip line of the plant. We find a good rate to be 1-2 cups of each, depending on the size of the plant. If your soil's pH is at a good level, skip the lime and use 2 cups of the Azomite and fertilizer only.
The soil amendments are lightly worked into the ground.
This final step of ‘scratching’ the soil amendments and fertilizer into the ground is very important. If simply left on the surface, they will cake and not break down into the soil as quickly.
Once green growth has commenced (in a few weeks), we will begin fertilizing the peonies with Neptune’s Harvest. For areas, where fungus is an issue for us, we apply an organic fungicide like Monterey Complete Disease Control.