Trott: September gardening tips

Fall care for flowers, trees, shrubs, fruits and vegetables

With our first frost, and the red winged blackbirds gathering to fly south, autumn has officially arrived in our neck of the woods. It is the ideal time to get out in your garden and plant, divide and get ready for the winter to come.

Here are a few tips for garden chores this month.


Many perennial flowers including peonies, daylilies and tall garden phlox may be divided in early fall. Dig the old clumps with a spading fork and split the crowns into several pieces using a sharp spade or large knife. Each new clump should contain part of the crown with several buds or “eyes” and a large part of the roots. Prepare new planting areas by mixing in compost or peat moss and replant at the correct depth (eyes should be only 2 inches deep for peonies to bloom well). Water well and mulch in late fall to prevent winter injury.

Apply water soluble fertilizer to your containers and hanging baskets to keep the plants healthy and blooming.

Daffodils planted this month will provide welcome color early next spring. Drifts of a dozen or more bulbs of one variety make the most impact and can be easily planted by digging the whole planting area 6-8 inches deep. Space the bulbs according to the package directions, fill in the soil and water well. Bulb fertilizer may also be incorporated below the bulbs.


Trees and Shrubs

Fall is a great time to plant trees and shrubs. The new plants will have several months to develop new roots and will be ready to grow early next spring. Consider adding some plants with great fall color such as sugar maple, burning bush or the University of Minnesota hardy blueberries including Northblue, Northsky and Polaris.

Trees that bleed or are susceptible to disease if pruned in the spring may be pruned now. This includes maples, birch, black walnut, oaks, honey locust and mountain ash. Prune young trees to a single central leader; remove broken, crossed or rubbing branches; and gradually remove lower branches. Always make proper pruning cuts just beyond the branch collar but not leaving stubs.

Fruits and Vegetables

Minnesota grown apples are ripening and are available at local orchards, fruit markets and grocery stores through mid-winter. If you grow your own apples, pick them just when the color and flavor peaks and while they are crisp and juicy. Zestar! is a new University of Minnesota introduction that has great flavor and texture and keeps well for an early apple. Honeycrisp is also a University of Minnesota release and is becoming nearly everyone’s new favorite apple. Look for Honeycrisp apples after Sept. 15.

Squash and pumpkins should be harvested when they have bright color and a thick hard skin. These vegetables will be abundant in farmer's markets and stores and make a colorful and healthy addition to fall dinners.

For more information about gardening in Minnesota, visit

Until next time, happy gardening!


“Autumn leaves don't fall, they fly. They take their time and wander on this their only chance to soar.” —Delia Owens, "Where the Crawdads Sing"


Robin Trott is a horticulture educator with University of Minnesota Extension. Contact her at 320-762-3890, or at trot0053@umn.

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