![Monthly Gardening Checklist](/sites/default/files/styles/hero/public/2023/03/29/banner_monthly_checklist_4.jpg?itok=P2BCXD_5)
![Monthly Gardening Checklist](/sites/default/files/styles/hero/public/2023/03/29/banner_monthly_checklist_4.jpg?itok=P2BCXD_5)
The Chicago Botanic Garden has 385 acres of nature, beauty, and respite to discover.
Members: 8 a.m. – 10 a.m.
Public: 10 a.m. – 8 p.m.
8 a.m. – 7 p.m.
10 a.m. – 7 p.m.
Harvest vegetables
Test your soil
Start a compost pile
Think spring bulbs
Plant a tree or shrub
Plant trees and shrubs
Keep watering
Postpone fertilizing
Keep deadheading
Leave perennials standing
Plant asters and mums
Divide peonies
Fruit, Vegetable,
and Herb Care
Fall harvest
Tend to raspberry bushes
Fall makeover
Bring houseplants inside
Overwinter tropical plants
Bring herbs indoors
Start new indoor plants
Although September ushers in autumn, with its shorter days and cooler nighttime temperatures, it may be the busiest of months for many gardeners. Vegetable gardeners have their hands full—literally and figuratively—harvesting peak warm-season crops and planting cool-season vegetables. Cool-season annuals can replace summer varieties in containers. Lawn tasks, including seeding and fertilizing, can begin in earnest. September also is a good month to plant many varieties of trees and shrubs.
Continue to harvest vegetables
The next six weeks will provide an abundance of produce. Continue to harvest vegetables as they ripen.
Test your soil
Consider taking a soil test of your entire yard or specific garden areas if you have not done this before. Understanding the makeup of soil will help you amend it properly to provide the nutrients it needs.
Contact the Garden’s Plant Information Service for a complete listing of soil-testing agencies. Follow agency instructions on where and how to collect soil samples.
Start a compost pile
If you didn’t start a compost heap in the spring, September is a good time to make one. Begin to layer grass clippings, dried fallen leaves, soil, a handful of fertilizer, and a little moisture.
Think spring bulbs
Make final selections of spring-blooming bulbs to plant in October and into November, provided the soil is workable and not frozen. Want to see flowers as soon as possible next year?
Plant a tree or shrub
Autumn is a great season to plant many trees and shrubs, as long as they are planted early enough to establish strong root systems.
Annual and Perennial Care
Fruit, Vegetable, and Herb Care
Keep deadheading
Continue to deadhead annuals to encourage additional flowers and to keep the plants looking tidy.
Leave perennials standing
Remove spent blooms on perennials but do not cut them back until their leaves and stems have lost all green color.
Plant asters and mums
Asters (Aster spp.) and mums (Chrysanthemum spp.) purchased in bloom this month are usually greenhouse-grown and not necessarily hardy. Plant early in the month in garden beds to increase their chances of making it through the winter. This should give plants four to six weeks to establish their roots before the Chicago area’s first frost. Water well after planting.
Divide peonies
Peonies (Paeonia spp.) can be divided and planted early this month, to help their root systems become established before winter.
Keep up with the fall harvest
It’s important to continue picking vegetables as they ripen. Remove diseased plants immediately, as well as those that have finished their growth cycle for the year. Compost only healthy plant material.
Tend to raspberry bushes
Ever-bearing raspberry bushes will produce their fall crop on the top half of the canes. After harvest, prune out the top half of the plants. The lower half of the canes will produce fruit early next summer. After harvesting the summer crop, prune the canes to the ground.
Lawn Care
Tree and Shrub Care
Seed the lawn
Early this month, entire lawns or bare patches may be seeded with an appropriate grass seed mix.
Address grub damage
Grubs, which chew grass roots, may be present if your turf begins to brown and lifts easily off the ground. Minor damage is usually not cause for treatment.
Aerate the lawn
Consider core-aeration, which removes plugs of soil and grass at regular intervals throughout the lawn. Aerating helps rectify compacted soil, reduces heavy thatch accumulation, and may improve drainage. Professional lawn services can provide the service or equipment can be rented.
Time to fertilize
September’s typically moderate temperatures, cooler nights, and adequate rainfall can spur grass growth, making mid-month a good time to feed turf with a fertilizer. Choose a product formulated for turf.
Plant trees and shrubs
Many trees and shrubs can be successfully planted in the fall, when moderate daytime and cooler night temperatures are ideal for planting. The warm soil and the return of autumnal rains provide good conditions for woody plants to establish their root systems before going dormant.
Water deeply and thoroughly at planting time and once a week until the ground freezes.
Keep watering
Continue to water large trees and shrubs, especially evergreens, as well as plants that are 1 or 2 years old, until the ground freezes hard. Evergreens will continue to lose moisture through their needles throughout the winter and need adequate water in their root zones to avoid winter burn or desiccated needles.
Postpone fertilizing
Wait until October to fertilize any tree or shrub that looks like it might benefit from extra nutrition—signs include stunted growth, failure to fully flower or leaf out, undersized fruit, and/or off-color foliage. Avoid fertilizing newly planted trees until they are fully established, which may take a few years.
Outdoor Container Care
Give containers a fall makeover
The return of cool weather is a good time to refresh annual containers with cool-season favorites such as fall-blooming asters (Aster spp.), ornamental cabbage and kale, mums (Chrysanthemum spp.), and pansies (Viola x wittrockiana).
Indoor Plant Care
Bring houseplants back inside
Houseplants that have spent the summer months outside need to return indoors before nighttime temperatures dip below 50 degrees Fahrenheit.
Bring herbs indoors
Some herb plants can be dug and brought inside for a winter windowsill garden.
Overwinter tropical plants
Some cold-sensitive tropical plants, such as tropical hibiscus (Hibiscus rosa-sinensis), mandevilla (Mandevilla splendens), geranium (Pelargonium), and plumeria (Plumeria) can be brought indoors for the winter.
Start new indoor plants with garden cuttings
Cuttings from favorite or unusual varieties of annuals, such as begonias (Begonia spp.), coleus (Plectranthus spp.), geraniums (Pelargonium spp.), and impatiens (Impatiens spp.), can be taken this month, potted up, and brought inside to a south-facing window.
September is a great month to …
start a winter herb garden
Gardeners can extend the life of their favorite outdoor herb plants by bringing cuttings indoors to grow, or buying herb seedlings or seeds at the garden center. If using garden cuttings, dig up selected herbs such as chives (Allium schoenoprasum), lavender (Lavandula spp.), oregano (Origanum spp.), rosemary (Rosemarinus officinalus), and thyme (Thymus spp.). Cut back the herbs; repot them in small pots with drainage holes that contain a light soil mix. Remember that herbs need 5 to 6 hours of sunlight each day, so a south-facing window or grow lights will be in order.