University of Illinois Extension

Fall Gardening Tips

Cool, crisp weather has finally arrived after a very hot, humid and wet summer, said Ron Wolford, U of I Extension horticulturist.

“Planting bulbs is probably the number one garden activity that takes place in the fall, but there is a number of other gardening and fall related activities to do,” said Wolford, who provided some tips for other tasks.

Get Ready for Frost

“Get ready for frost,” he said. “On average our first fall frost occurs around October 15, but we have had frost in September. First frosts usually occur when cool weather arrives with clear nights and light winds.

“Open grassy areas are most likely to have frost versus areas under trees that are protected because the trees keep heat from escaping. Plantings close to the foundation of your home often survive a first frost because of the heat given off from house. To protect plants cover them with blankets, newspaper, straw, sheets, tarps, boxes, or plastic sheeting. Apply the covers later in the afternoon and remove them in the morning. Floating row covers can also protect plants. This spun polyester material will raise the temperature two to five degrees F around the plants.”

Plant a Green Manure Crop

Green manure crops include clover, annual ryegrass, winter wheat, winter rye and buckwheat. Green manure crops turned into the soil in the spring will improve soil structure and will add organic matter and nutrients to the soil. Sow the seed thickly. Keep moist until germination occurs. Cut back plants that flower to prevent self-seeding. In early spring turn the green manure into the soil.

Transplant Perennials

“Transplant and divide perennials now,” Wolford recommended. “If you are planning to transplant established plants, cut them back by half and move to a prepared spot. Keep watered until the plant is established.

“Divide perennials when flowers get smaller, when the center of the plant dies out or when the plant just gets too big. All transplanting and dividing should be completed by October 1 to allow good root development before cold weather sets in.”

Repair Lawn

Autumn is the best time to repair lawns. Seeding bare spots in the lawn from early to mid-September will allow the new growth to have enough time to germinate, grow and harden off before cold temperatures arrive. There is less competition from weeds in the fall because a lot of the annual weeds are dying out. Plus we are usually blessed with cool temperatures in the fall which is great for growing grass. Ideally dig the soil to at least 6-8 inches deep, spread grass seed over the area and tamp down. Keep the soil moist until germination. Cover with weed free straw to conserve moisture. If you are laying down sod, water the new sod several times a day for 1-2 weeks until it begins to knit or take hold. Be sure that water goes down through the thick sod and moistens the soil underneath for good root development. Do not let sod dry out.

Start a Compost Pile

“Fall is a good time to start thinking about starting a compost pile,” he said. “As we go later into the fall, dying plant material is more readily available for composting, plus you have all the fallen leaves. For more information on composting, check out the University of Illinois Extension website: Composting Central .”

Plant Trees

Plant trees, shrubs and evergreens through September. Planting during this time period will allow the plant to become established before winter sets in. Water plants every seven to 10 days during dry weather until the ground freezes.

Garden Clean-up

Remove dead plants from the vegetable garden after frost. If plants were not diseased, they can be turned into the soil or placed in a compost pile. Leaving dead plants in the garden will provide a home for over wintering insects. Spread a two to three inch layer of organic matter over the garden and dig in. The garden will be ready for planting in the spring.

Prepare Amaryllis for Flowering

Stop watering amaryllis in late summer to revive the bulb for flowering. Let the leaves die. Cut the dead leaves off to within two to three inches of the bulb. Place the potted bulb in a cool, dark place like the basement for six to eight weeks. Bring the amaryllis into a bright, warm area and start watering. Keep the soil moist. It should bloom in four to eight weeks after the start of watering.

“For more gardening information, check out the University of Illinois Extension website: Hort Corner at,” said Wolford.