Your "to do" list for the month

Sunflower in the UT Gardens, Knoxville

Sunflowers are still prominent in September at the UT Gardens, Knoxville. Photo by J. Newburn, courtesy UTIA.

Here is your “to do” list for the garden for the month. These tasks may not apply at everyone, but September is a good time to perform any of these tasks that will enhance your landscape. The tasks were submitted by Jason Reeves, horticulturist and curator at the University of Tennessee Gardens in Jackson.
● Apply a pre-emergent herbicide on your lawn to control cool-season weeds such as chickweed, henbit, dead nettle and annual bluegrass (Poa annua).

● Fall is a pleasant time (if there is such a thing) to work with stone.

● Keep an eye out for pests on your pumpkins, gourds, squash and melons. Cucumber beetles and squash bugs can be controlled with Sevin. Harvest your pumpkins when their color deepens and skin yields very little to pressure. Wash the fruits in a weak bleach solution and store them in a cool, dry location until you are ready to display them.

To ensure proper maturity, hard-shelled gourds such as dipper, birdhouse and swan should be left on the vine until the vine starts to die back.

Divide and re-pot any tropicals you have outdoors to prepare them for their winter home. Hose off or wash plants with soapy water and inspect them for insects. If needed, treat them with an appropriate insecticide. Imidacloprid, the active ingredient in many of the new insecticides, is a good systemic for insect control. It can be mixed with water and poured on the soil and the plant will take it up.

Collect seed heads and pods on plants like okra, sumac, cotton, coneflower, rose hips and other suitable materials for dried arrangements. Air-dry in a dark, well-ventilated, cool location.

If you have had disease problem with any of the vegetables in your garden, remove and dispose of the plant materials properly. Do not add these to the compost pile. Many diseases will over-winter on infected leaves, stems and fruit. This tip is especially important with tomatoes.

Allow plants to finish the summer growth cycle in a normal manner. Never encourage new growth with heavy applications of fertilizer or excessive pruning this late in the season. Plants will not properly harden off and new growth can be injured by an early freeze.

Avoid the temptation to plant seasonal pot mums in your landscape. Even if they establish themselves, they rarely live up to your expectations the following year. It is best to just toss them onto the compost pile after they fade. Chrysanthemum 'Clara Curtis' and 'Sheffield Pink' are good, reliable cultivars that will be around for years to come.

Order or purchase bulbs by October 1 for availability of the best selections. Store them in a cool, dry location until you plant them. Colchicum and fall-blooming crocus should be planted as soon as they arrive.

Keep deadheading plants such as zinnia and cosmos to ensure that they continue to flower. Continue collecting annual and perennial seeds that you wish to sow next year. Freshly collected seed is best stored in a paper bag or envelope until thoroughly dried.

● Begin planting cabbage, kale and pansies in the latter part of the month.

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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.



Jason Reeves
, UT West Tennessee AgResearch and Education Center, 731-424-1643