If you’ve been waiting for cooler weather to finish your garden-chore to-do list, now is the time to get going. September gives gardeners a second chance to get around to unfinished garden tasks. Here’s a checklist to get you started:
Trees and shrubs
Fall is a great time to plant trees and shrubs. Be sure to plant trees properly by making sure that the trunk flare is above the soil level. For planting directions, consult the International Society of Arboriculture Web site, www.treesaregood.com/treecare/tree_planting.asp.
Prune broken and dead branches. Avoid severe pruning now; wait till February or March for most trees and shrubs.
Handpick bagworms from evergreens. Make a game of it — offer your children or grandchildren 5 cents a piece for each bagworm.
Plant frost-tolerant flowers such as pansies, flowering kale, chrysanthemums, and asters.
Purchase spring-flowering bulbs such as daffodils and tulips for planting in early October.
Cut flowers for drying. Strawflowers, celosia, globe amaranth, and baby’s breath dry nicely. Hang flowers upside down in a warm, dry location.
Dig gladiolas and dahlias as the foliage yellows.
September is a good time to divide most perennials, and it’s the best time to divide peonies. Be sure to have three to five eyes per peony division. Replant so that the eyes are no more than 2 inches deep.
Stop fertilizing roses.
Reseed bare spots. Select good-quality turf mixes or blends appropriate to the site. In central Illinois, seed before Sept. 15.
Around Labor Day, apply nitrogen at a ratio of 1 pound actual nitrogen per 1,000 square feet.
Continue mowing; mow to maintain a height of 2 to 2 1/2 inches.
Leave grass clippings on the lawn, where they will decompose.
Vegetables and fruits
Continue harvesting vegetables.
Pick apples when the flavor is sweet but before the fruit softens. Store in a cool place.
If you have not already done so, dig potatoes with a fork or shovel and allow them to air-dry for a week. Store potatoes in a cool, dark location.
Plant radish, lettuce, and spinach for fall harvest.
Harvest winter squash when the rind is hard but before the first hard frost.
Harvest grapes and everbearing strawberries.
Remove weeds from garden plantings to keep them from going to seed.
Harvest herbs. Rinse with water, air-dry, and hang clean stems upside down in a dark location. Allow to completely air-dry before storing in airtight containers.
In late September, dig and repot herbs such as rosemary and lavender for use indoors.
Before night temperatures drop below 55 degrees Fahrenheit, bring houseplants indoors. Rinse the leaves with water or wipe them with a damp cloth, and wash the outside of each container. Carefully inspect plants for insects and diseases. Acclimate plants by gradually decreasing the amount of light the plant receives.
Store unused garden seed in a cool, dry place.
The first of the University of Illinois Extension’s fall gardening series looks at exotic invasive plants and the impact of these plants on the state’s natural resources. Horticulture educator Chris Hilgert discusses 11 exotic invaders, as well as provisions of two state laws that regulate the importation and cultivation of certain weeds and invasive plants.
The seminar, which will be held at the U of I Extension building at the Illinois State Fairgrounds, is offered at 1 p.m. Tuesday, Sept. 6, and 7 p.m. Thursday, Sept. 8. There is a $2 charge. For more information and to reserve a seat, call 217-782-4617.