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Putting your perennial plants to bed in the winter can be confusing. Some plants are very beneficial to wildlife and add beautiful textures to the garden in winter and should be left alone. But some plants need to be trimmed back to promote healthy growth and to prevent plant diseases.

The time to cut back perennials is after at least one hard frost. Use a leaf blower to remove trimmed foliage from the area. Don't put any diseased foliage in the compost pile.

12 to Cut Back

1. Columbine: cut foliage down to the ground and mulch. Dispose of any foliage affected by leaf miners by burning or in the trash, do not compost it.
2. Yarrow: cut any old foliage down but keep new basal leaves to protect the crown during winter.
3. Bee Balm: cut foliage down to 1 inch above the soil to discourage problems like mildew.
4. Peonies: prune stems within 2 inches from the ground. Peonies are also susceptible to mildew. Cutting back peonies before the first frost can limit next year's number of blooms.
5. Garden Phlox: cut down to 1-2 inches above the soil to prevent powdery mildew.
6. Liatris - Blazing Star: trim flower spikes and leaves to the base of the plant.
7. Hollyhocks: cut down to about 6 inches high to reduce the risk of leaf rust. Scatter seedpods for more plants in spring.
8. Hostas: prune hosta leaves near the crown. Keeping hostas clean from dead leaves helps prevent slugs from destroying plants come spring.
9. Chrysanthemum: Cut back mums that are 2 years old or more after they've finished blooming or been hit by a hard frost. Use mulch to insulate the plant from harmful freeze and thaws. First year mums leave growth on to help keep mulch in place.
10. Iris: they are susceptible to the iris borer which will kill the iris plant. Iris can be spread with Hi-Yield 38 Plus to prevent infestations. The female moth lays eggs in plant debris where they overwinter, so it is especially important to clean up around the plant and remove all dead leaves and debris. Trim the fan of the sword-shaped iris leaves at an angle so they slope upward into a center peak no higher than 6-8".
11. Daylilies: cut leaves within 2 inches above the ground at the base of the plant.
12. Lilies: cut the stalk near the soil line after the leaves discolor.

7 to Let Be

1. Helleborus - Lenten Roses: semi evergreen foliage should be cleaned in the spring, not the fall.
2. Coral Bells - Heuchera: due to semi evergreen foliage, this plant should be cleaned in the spring.
3. Russian Sage: adds texture and shelter in the winter garden.
4. Coneflowers - Echinacea: seed heads add an important food source to winter birds.
5. Perennial Hibiscus: is one of the last perennials to come up, so leave the stalks in place so you know where they are. As new leaves emerge trim the old growth as needed.
6. Sedum: is a plant you can mostly leave alone. Larger varieties add interesting textures to the garden in winter.
7. Ornamental Grasses: dried ornamental grasses such as miscanthus, little bluestem or fountain grass can look beautiful in the winter or can trap snow and help insulate plants and shelter wildlife.