HOW TO DIVIDE PEONIES
Suzanne Knutson, Wilton Garden Club
Tools needed: Shovel, sharp knife, clippers and a tarp
- Peony roots reach to the drip line of the plant. Start digging at the drip line so you will not be cutting off any roots.
- Clean the soil off the plant so you can locate where to divide the Peony, being careful not to damage any of the eyes. The eyes are what the plant will bloom from the following year. Eyes
grow on last year’s stems.
- Once the soil is off, clean up the plant by removing this year’s growth located next to the new eyes.
- When dividing, use a sharp knife. Each new plant division should have 3-5 eyes.
- Insert the knife between the stems and eyes.
- Clip all oversized roots to 6”-8”, to promote new growth. The older plant will be darker in color.
- Plant the new divisions 2”-3” below the surface and water well.
- Plants only need to be divided every 10-15 years, or sooner only if they are not flowering well.
- Cut back the foliage and discard into the trash. Do not compost peony leaves because they can harbor botrytis.
HOW TO DIVIDE AND CLEAN UP BEARDED IRISES
- A bearded iris is an underground stem called a rhizome. Rhizomes grow horizontally underground, producing buds that will become sprouts. The sprouts will eventually grow above
ground creating new plants.
- Best time to divide irises is in July, because this is the only time of year that they produce new roots.
- Lift the iris out of the ground, knocking off any remaining soil.
- Examine the plant for any pinholes in the rhizome, cutting these off and discarding into the trash. The pinholes are made by borers and continue to infect the plant if you leave even one pinhole in the rhizome.
- Once clear of all pinholes, leave the rhizomes in the sun for an hour or two before replanting. This allows the rhizome to callous over the cut areas, eliminating the need for any chemicals. Organic is the way to go!
- Plant the rhizomes only half-buried in the soil, because they like to be slightly exposed to the sun. They won’t flower well if the rhizome is buried too deep in soil.
- Make a bump using soil in the middle of the hole and place the rhizome atop the ridge, taking care to spread the roots out and down. Leave 10”-12” between plants to allow the rhizomes to grow laterally. Partially cover with soil, and then water them.
- Trim the iris foliage back to 6”, which will promote root growth and prevent them from toppling over.
- Irises require well-drained soil and at least a half-day of sun, 8 – 10 hours is preferable.
HOW TO CLEAN BEARDED IRISES IN THE FALL
- Wait until the foliage starts to die back in the fall before removing it. Pull each leaf off, one at a time, away from the center, and discard into the garbage; do not compost.
- Remove all the leaves until you get to the two center leaves that create a “V” – do not remove or damage these leaves.
- If you take time to clean the foliage off your irises, you will be removing all the new borers. The borers lay their eggs on the leaves where they overwinter.