From the Ground Up: Get ready to cut back this fall

Fall yard and garden clean up is well underway but do you know when the right time is to cut back plants in the home garden? It depends on the plant. Iowa State University Extension and Outreach horticulturists Richard Jauron and Greg Wallace offer the following tips.

When should I cut back perennials?

Most perennials, such as peonies, daylilies and hostas, can be cut back in November after a hard freeze has destroyed the above ground growth. If fall cleanup isn't possible, it's still ok to remove the dead debris in early spring.

When should I cut back ornamental grasses?

Many ornamental grasses provide color, sound and movement to the winter landscape. Because of these winter features, cut back ornamental grasses in April in Iowa. Cut back the grasses to within 3 to 4 inches of the ground with hand shears, lopping shears or hedge trimmers.

When should I cut back asparagus?

Asparagus foliage can be cut back to the ground after it has been destroyed by cold temperatures in fall. However, it's best to allow the dead foliage to stand over winter. The dead debris will catch and hold snow. Snow cover helps protect the asparagus crowns from cold winter temperatures. Asparagus foliage allowed to remain in the garden over winter should be removed in late March or early April before spears begin to emerge.

When can I cut back rhubarb plants?

Don't cut back the rhubarb until the foliage and stalks have been destroyed by a hard freeze. To produce a good crop next spring, rhubarb plants must manufacture and store adequate levels of food in their roots. The foliage continues to manufacture food as long as it's healthy. Once destroyed, the foliage and stalks can be removed.

Do I need to rake the leaves on my lawn?

Turfgrass plants utilize light, water and nutrients to manufacture food. In fall, lawn areas beneath large trees are often completely covered with leaves. The leaf debris prevents the turfgrass plants from manufacturing and storing food prior to winter. Additionally, the leaves of some tree species mat down readily and may smother the grass. Thick layers of leaves should be raked up and removed. Small amounts of leaf material can be shredded with a mower and left on the lawn.

When can I stop mowing the lawn in fall?

Continue to mow the lawn until the grass stops growing. The foliage of Kentucky bluegrass and other cool-season grasses usually stops growing in late October or early November in Iowa. But we have had a fairly mild fall to date. Mow lawns at a height of 2 1/2 to 3 inches in fall. When mowing the lawn, never remove more than one-third of the total leaf area at any one time.

• For additional fall gardening questions call the Linn County Master Gardener Hortline at (319) 447-0647.