8 Perennials You MUST Divide in October (And 7 to Never Touch), by Urban farming on YouTube. 15 min 59 s.
- Video length
- 15 min 59 s
- Time to do it
- 1 hour
- Difficulty
- Easy
- Steps
- 8
What you need
Steps
Find your first hard freeze date for your area. Count back four to six weeks. That window is your real deadline for dividing, so work backwards from it.
Check the root type before you dig. Clumps, rhizomes and crowns divide safely. Plants with one deep taproot do not, so leave those in the ground.
Water the plant the day before. Lift the whole clump with a garden fork, working around it and under the root ball to keep it intact.
Cut the clump into sections with a sharp knife or saw. Keep the healthy outer pieces and discard the woody, hollow centre.
Replant the divisions at the same depth they grew before, spacing them apart. Firm the soil around each piece and water well.
Divide hostas, daylilies, garden phlox, Siberian iris, peonies, bearded iris, rudbeckia and Shasta daisies now. Set bearded iris rhizomes shallow, with the top just above soil.
Leave sea holly, baby's breath, butterfly weed, baptisia, oriental poppy, Madonna lily and tall sedum alone. Their roots resent being cut.
Mulch the new divisions after the ground cools, not straight away. Keep mulch off the crowns so they do not rot.
Tips and common mistakes
Plant peonies no deeper than 2 inches above the buds, or they may stop flowering for years.
If your freeze is less than four weeks away, pot the divisions and overwinter them in a sheltered spot instead.
Do not divide a plant that is already weak or diseased, since it may not recover before winter.
Questions
Can I divide perennials in October if frost is close?
Only if you have at least four weeks before the first hard freeze. Less than that and the new pieces may not root, so pot them and keep them sheltered.
Why should I not divide oriental poppy or tall sedum?
They have deep taproots or fragile crowns that heal slowly. Cutting them in autumn often kills the plant or leaves you with pieces that rot over winter.
How deep do I plant peony divisions?
Set the buds no more than 2 inches below the soil surface. Deeper planting is the main reason peonies stop blooming.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
