General Garden Care Checklist
Cool-season annuals that can tolerate a light frost can be planted out early in the month after being hardened off. These include snapdragons, sweet peas, English daisies, pot marigolds, African daisies, lobelias, sweet alyssum, forget-me-nots, pouch flowers (Nemesia), baby-blue-eyes, larkspurs, love-in-a-mists, bush violets (Browallia), stocks, primroses, pansies, painted tongues (Salpiglossis), sweet Annie (Artemisia annua), and violets. Later in the month plant Shirley, Iceland, and California poppies, and Persian buttercups (Ranunculus).
Continue to remove all garden debris from last year. Shred and compost, leaving out diseased material. Add 2 to 4 inches of compost to garden beds if not done yet.
Plant trees and shrubs. Wait one year to fertilize new woody plantings.
Plant warm-season flowering annuals, vines, herbs, and vegetables after the Chicago area’s average last frost date of May 15. Cautious gardeners often wait until Memorial Day before setting out cold-sensitive plants such as tomatoes, peppers, eggplants, and squash. Pinch back one-third of new growth to encourage stocky habit (except vines). Be sure newly purchased annuals have been hardened off properly before planting them outside. Avoid fertilizing newly planted annuals for two weeks.
Continue to plant new perennials, ornamental grasses, and roses in containers. If plant roots are root-bound (encircling the pot), make four cuts into the bottom of the root ball with a sharp tool, and flare the sections outward when planting.
Provide a gentle water drip for migrating birds. The May migrants — warblers, tanagers, orioles and buntings — are all attracted to shallow pools and the slight pinging sound of dripping water.
Apply 1 to 2 inches of leaf mulch on flower beds and around trees, keeping mulch away from the trunks. Mulch conserves moisture, protects plant roots, suppresses weeds, and regulates soil temperature. Make sure all trees, shrubs, perennials, and roses receive 1 inch of water per week. If Mother Nature does not provide this amount, it is best to water deeply once per week rather than water shallowly several times per week.
Newly planted trees, shrubs, perennials, and roses must receive 1 inch of water per week throughout their root zones. This is especially important in hot, dry weather.
Continue to cultivate and weed. The return of hot weather will certainly push weed growth.
If not done yet, mulch garden beds immediately after weeding with 2 to 4 inches of shredded bark. This is the best way to retain moisture and keep weeds under control.
Continue to water, weed, and monitor for insects on all garden plants. In times of drought, prolonged hot weather or water restrictions, first water all newly planted trees and shrubs, newly planted perennials and vines, and newly sodded or seeded lawns. Annual plants should be the last on the list, simply because of their ephemeral nature.
September is a good time to begin a compost heap. Begin to layer grass clippings, dried fallen leaves, soil, a handful of fertilizer, and a little moisture. Shredded garden debris can be added as annuals and perennials die back next month.
Pick a dry day this month to test your soil. Plant Information at (847) 835-0972 has listings of soil testing agencies. Follow agency instructions on where and how to collect soil samples. Refrain from adding amendments, fertilizers, or other chemicals to your soil until you know what your soil lacks.
Keep the compost pile active by adding layers of green material (grass clippings and frost-killed annuals or perennials) and brown dried material (fallen leaves, shredded twigs, and dried grasses) with small amounts of soil, fertilizer, and moisture. Turn regularly. Keep diseased material out of the pile.
Excess fallen leaves can be shredded and kept aside to use later next month as mulch for perennial and garden beds once the ground has frozen hard.
Add 2 to 4 inches of shredded leaves, composted manure, or garden compost to perennial borders and garden beds once the ground has frozen completely.
Continue to feed the compost pile with grass clippings and dried plant material removed from garden beds. Avoid adding diseased plants to the pile. Turn the pile regularly to speed decomposition.
Before temperatures go below freezing, disconnect outside water sources, drain hoses, and store indoors. Sharpen and oil tools. Store all unused herbicides, pesticides, fertilizers, and chemicals in original, labeled containers. If cardboard containers have become wet, consider disposing of the product. Avoid storing chemicals in unmarked plastic or glass containers because it’s too easy to forget what they are. Check expiration dates on products to be sure they’re still viable.
Clean birdbaths, but try to maintain a water supply for birds over winter. Small heating coils can be used in stone birdbaths to prevent water from freezing.
Clean and refill bird feeders. Regularly cleaning and rinsing bird feeders is essential to prevent spread of disease.
All ceramic, cement, or terra cotta containers should be emptied, cleaned, and stored in a frost-free space. Soilless mix from containers can be stored in a pile outside and combined with equal parts fresh mix for next year’s containers.
In the event of snowfall, avoid using salt-based de-icing products in or around garden areas. Shovel snow before it freezes on sidewalks and sprinkle sand on walkways close to plantings.
Mulch perennial beds once the ground has frozen hard. Apply 2 to 4 inches of shredded bark, composted manure or garden compost, if not done already. Evergreen boughs from seasonal wreaths or small sections of Christmas tree branches may also be used as winter protection on garden beds.
If ice forms on surface of aquatic garden pond, pour warm water over it. Banging ice with heavy object can injure fish.
Try to avoid salt-based de-icing products in or around garden areas. Sodium chloride products are more damaging to plants than potassium- or calcium-based products. Always shovel before spreading de-icing material.
When shoveling snow, try to distribute snow equally on garden plants instead of piling it up against foundation plantings or in the root zone of one tree.
If possible, maintain a supply of water for birds over winter. Small heating coils can be used in stone birdbaths to prevent water from freezing.
Clean and refill feeders. Regular cleaning and rinsing is essential to prevent spread of disease to visiting birds.
Order seed, bulb, and nursery catalogs to assist in planning your garden for the new year. To help you choose the best plants for your garden, take advantage of the Garden's online resource Illinois' Best Plants, as well as its Plant Information Service, Lenhardt Library, and the Joseph Regenstein, Jr. School of the Chicago Botanic Garden. See seed-starting advice in "Indoor Plant Care" below.
Recycle Christmas tree branches (cut into 2- to 3-foot sections), swags, wreaths, and other evergreen material as mulch for garden and perennial beds. Lightweight, open evergreens permit moisture to reach the soil but also insulate the roots and crowns of plants from the freeze-thaw-freeze cycle of Midwest winters. An alternative use for a holiday tree is to set it in the backyard and decorate it with bird seed and suet ornaments for winter birds. Continue to supply fresh water for birds.
When clearing driveways or shoveling walks, distribute snow loads equitably on shrubs and garden beds.
Continue to use potassium- or calcium-based deicing products on walkways rather than sodium-based ones. If possible, broadcast sand on slippery surfaces. Always shovel snow before using any de-icing product.
During periods of winter thaw, water garden beds, turf, and plants that have received salt spray from roads.
Monitor plants for signs of damage from animals, ice, snow, or wind.
Keep ponds free of ice by installing small pumps or pouring warm water over ice as it begins to form. Don’t bang ice with a heavy object if you have fish in the pond.
Continue to keep the garden tidy by removing any broken or fallen branches from the yard. If small plants have heaved out of the ground, gently press them back with your hands; avoid compressing thawed ground with heavy boots. Retie any vines that might have been torn from their supports.
Continue to order seed, bulb, and nursery catalogs to assist in planning your garden for the upcoming year. To help you choose the best plants for your garden, take advantage of the resources of the Chicago Botanic Garden's Best Plants Web site, the Plant Information Service, Lenhardt Library, or the Joseph Regenstein, Jr. School of the Chicago Botanic Garden.
Unseasonably warm and dry winter weather will further stress plants that were not watered adequately during a dry Chicago autumn. During periods of winter thaw, water evergreens, broadleaved evergreens, and conifers as needed. Water newly planted trees and shrubs and all plants, including turf, that might be in the path of salt spray from salted roads.
Continue to check plants for signs of damage from weather or animals.
If necessary, continue to use potassium- or calcium-based de-icing products on walkways rather than sodium-based products. If possible, consider using sand on slippery surfaces. Always shovel snow before applying any product.
On dry days remove winter debris from lawn and garden beds. Check for broken branches (prune immediately) or plants damaged by snow loads or rodents. Remove burlap screens erected to protect plants from wind or road salt spray.
Consider a soil test of your entire yard or specific garden areas if you have not had one before. Consult the results of the test before adding amendments to your soil. Soil temperature must be 50 degrees for a proper reading. Tests can also be performed in the fall. Contact Plant Information at the Chicago Botanic Garden at (847) 835-0972 for a complete listing of soil-testing agencies.
To avoid compacting garden soil, wait until it has dried out before tilling, planting, or even walking in the garden beds. Mix in 6 inches or more of compost or leaf mold to lighten heavy soil.