October Gardening Tips from the UT Gardens

Despite autumn’s arrival, there is still plenty to do in the garden. For example, October is the preferred time to plant ornamental kale, Swiss chard and pansies. These are lovely additions to the fall and winter landscape, as well as being edible. Look for the winterbor and Russian kales as they are more reliable in cold weather than the kales known commonly as “flowering cabbage.”

Here are more items for your “to do” list for the garden for the month. These tasks may not apply at everyone, but October is a good time to perform any of these tasks and they will enhance your landscape. The tasks were submitted by Jason Reeves, horticulturist and curator at the University of Tennessee Gardens in Jackson.

• Remember that seasonal mums are more valuable as compost than as “keep around plants” after they’ve faded and split. Don’t be tempted to plant them! Even if they establish themselves, they rarely live up to your expectations the following year. Chrysanthemum ‘Clara Curtis’, ‘Ryan’s Yellow’, and ‘Sheffield Pink’ are good reliable perennial cultivars that perform well in the landscape. ‘Fireworks Igloo’ from Blooms of Bressingham is a newer introduction of perennial mum that performed well in University of Tennessee trials in 2013 and this year. We have several more of the ‘Igloo’ series this year and so far so good.
• Warm season ornamental grasses such as Miscanthus and Pennisetum (fountain grass), resent being dug, divided and replanted in the fall. It is best to wait until early spring. As a general rule, avoid planting even container-grown warm season grasses in the fall. There isn’t sufficient time for the roots to establish, and the plants may be lost over the winter.
• Collect seed of any annuals you would like to grow again next year. Allow to dry completely before storing. A paper bag works great as a container that allows the seed to dry.
• You still have time to order bulbs, but be swift about it. Get them in the ground by early December.
• Before the first frost, dig up caladiums and shake off soil. Allow them to dry completely and store in a warm dry place for the winter.
• October is a good time to plant trees and shrubs, since dormant plants will be under less stress. Newly installed deciduous plants require almost no watering during the winter months, but don’t forget a thorough initial watering is paramount. Monitor evergreens such as junipers, hollies and arborvitae for watering needs if rain is sparse. Even in winter, a plant with leaves on it will transpire. Winter wind desiccation can hurt an evergreen tree that lacks sufficient moisture.
• Wash your pumpkins, gourds and winter squash in a mild bleach solution before displaying or storing to help prevent rot.
• October is a good time to control broad-leaf weeds such as white clover and wild garlic in your lawn. Check with your local county UT Extension office for specific recommendations.
• Don’t forget to bring in your tropical and house plants before frost. Many plants don’t like it when the temperatures drop into the 40s.
• After frost, you can cut back your deciduous herbaceous perennials. This helps lessen the chance of disease or insects overwintering in your beds. Perennials that are borderline hardy and may benefit from retaining their stems through the winter include hardy lantanas and salvias. Any tender plants such as cannas and elephant ears appreciate a layer of mulch for extra winter protection.
• Other perennials can be mulched with a thin layer of organic material, but keep the mulch away from the crown or it could hold too much moisture and rot the plant.
• Pick off any bagworms from your plants to help eliminate the eggs that will hatch next year. Dispose of them in the garbage and not the compost or they may survive and hatch.
• To make leaf removal less of a chore, rake them before they accumulate deeply. If you have a fescue lawn or moss garden it is even more important to keep the leaves removed. Compost or use them as mulch in your beds. You can also till them into your soil and by spring they will be composted. Leaves on the lawn can be chopped with the lawnmower and left in place if the debris is not too deep.

For more gardening tips, sign up for the UT Gardens free e-newsletter online at utgardens.tennessee.edu

The UT Gardens includes plant collections located in Knoxville, Jackson and Crossville. Designated as the official botanical garden for the State of Tennessee, the collections are part of the UT Institute of Agriculture. The gardens’ mission is to foster appreciation, education and stewardship of plants through garden displays, educational programs and research trials. The gardens are open during all seasons and free to the public.