Should You Cut Back Perennials in the Fall?

Short answer: Cut back soft perennials that turn to mush over winter, such as hostas, daylilies and peonies, and any plants with disease. Leave ornamental grasses, coneflowers and sturdy seed heads standing if you want winter interest and food for birds, and cut those back in early spring.

Cut back in the fall

• Hostas: the leaves collapse into slime and shelter slugs.
• Daylilies: the foliage flops and mats.
• Peonies: cut to the ground to reduce fungal disease.
• Bearded iris: trim the leaves to reduce pests.
• Anything diseased: remove and bag it, do not compost it.

Leave standing until spring

• Ornamental grasses: they hold snow beautifully and protect their crowns.
• Coneflowers and black-eyed Susans: seed heads feed birds.
• Sedum: sturdy stems look good under snow.
• Tender perennials: the old growth insulates the crown.

How to cut back

1. Wait until after the first hard frost when plants have gone dormant.
2. Use clean, sharp pruners or shears.
3. Cut to a few centimetres above the soil, avoiding new buds at the base.
4. Remove the debris from the bed.
5. Leave a light layer of shredded leaves as mulch if you like.

What to avoid

• Cutting everything to the ground out of habit.
• Pruning flowering shrubs in fall, which removes next year’s flower buds.
• Leaving diseased foliage in the bed.

When to call a professional

Garden bed winter prep is part of our fall yard cleanup. Tell us which plants you want left standing and the crew follows your list.

Questions homeowners ask

Is it bad to cut back perennials too early?

Cutting before dormancy can trigger new growth that frost then kills. Wait for a hard frost.

Should I cut back roses in the fall?

Only remove dead or damaged canes. Main pruning is done in spring.

What do I do with the cuttings?

Healthy material goes in yard waste bags. Diseased material should be bagged separately.