Fall Dividing Perennials: Which Plants to Split in Fall
Fall dividing perennials works for plants that bloom in spring and summer. University of Minnesota Extension says to time it four to six weeks before the ground freezes so roots can establish.
The short answer
Divide spring and summer bloomers in fall and save fall bloomers for spring. Minnesota Extension names peonies, Oriental poppy and Siberian iris as fleshy rooted plants that do well divided in fall. Dig the clump, split it into pieces with three to five shoots and roots, then replant and water.
Which perennials can you divide in fall?
Minnesota Extension lists peonies, Oriental poppy and Siberian iris. NC State Extension says outdoor perennials such as daylily, iris, liriope and verbena can be divided, normally in fall or early spring. See fall garden cleanup after cannabis harvest for fall bed work.
When is it too late to divide?
Minnesota Extension says to divide four to six weeks before the ground freezes, which matters most in colder northern areas. Pick a cloudy day and water the soil a day ahead if it’s dry.
How do you dig and split a clump?
Lift the plant with a spade or fork and shake off loose soil. Minnesota Extension says to pull roots apart by hand or cut them with a sharp knife or spade. You can also push two forks back to back into the center and pry. Shade divisions and hold them moist until you replant. Replant peonies at 1 1/2 inches deep. Moving plants is covered in transplanting marijuana plants, and soil prep in fertilizer and compost for growing outdoors.
Fall division guide
| Item | Guide | Source |
|---|---|---|
| Fall plants | Spring and summer bloomers | Minnesota |
| Timing | 4 to 6 weeks before freeze | Minnesota |
| Shoots per piece | 3 to 5 | Minnesota |
| Peony depth | 1 1/2 inches | Minnesota |
| Season | Fall or early spring | NC State |
Sources: University of Minnesota Extension, NC State Extension.
How to: step by step
- Pick plants that bloomed in spring or summer.
- Divide four to six weeks before the ground freezes.
- Water the clump the day before.
- Dig around and lift the whole clump.
- Split it into pieces with roots and shoots.
- Replant at the proper depth and water.
Troubleshooting
Divisions fail before winter: late planting. Divide earlier.
Weak regrowth: divisions too small. Leave three to five shoots.
Wilting: dry soil or sun. Divide on a cloudy day and water.
Kind Seed Co shares more garden notes on the blog.
Sources
- Dividing perennials, University of Minnesota Extension
- Extension Gardener Handbook, chapter 13: Propagation, NC State Extension
FAQ
Which perennials should wait until spring?
University of Minnesota Extension says to divide fall blooming perennials in spring, and to divide hostas in spring before they get too large.
How often should perennials be divided?
Minnesota Extension says to divide when the center dies out, flowers get smaller or blooming drops. Catmint, hyssop and Japanese painted fern can be divided every year if needed.
Can I divide plants in bloom?
Minnesota Extension advises dividing when the plant isn't flowering so its energy goes into new roots and leaves.
Do divisions need fertilizer?
Extension sources don't cover feeding divisions and focus on water, shade and timing.
Are there perennials you should not divide?
Minnesota Extension says Baptisia has long, deep roots and should not be divided or moved if possible.
