May Garden Checklist
For Chicago-area gardeners, May is typically “go time!” for planting annuals, vegetables, and herbs to fill out the garden. The lawn is actively growing, too. However, this month is a study in contrast, before and after the final frost date for the Chicago region’s USDA Hardiness Zones 5b and 6a. When planting warm-season annuals, vegetables, and herbs, proceed with caution if cold temperatures or frost are predicted, especially at night. In May, it pays to be patient and flexible.
Garden To-Do List
Harden off warm-season plants
Begin to harden off warm-season transplants in a cold frame, or bring flats of small transplants outside to sunny, protected areas. Do this for successively longer periods of time, typically seven to 10 days, to acclimate them to the outdoors.
Monitor overnight temperatures
It’s important that warm-season plants aren’t exposed to cold temperatures or hard frosts. Although May 15 is the recommended planting date for most of the Chicago area, frosts can and do occur after this date.
- Be prepared to protect new plantings and bring unplanted containers indoors if cold temperatures are predicted.
- It may be best to plant warm-season plants such as tomatoes, peppers, basil, cucumbers, beans, corn, impatiens (Impatiens) and zinnias (Zinnia spp.) at the end of May or even early June. Cautious gardeners often wait until Memorial Day before planting warm-season plants.
Keep track of precipitation
Government weather models indicate midwestern springs may begin to experience more rain in the coming seasons. Avoid working the soil if it is excessively wet. Soil should crumble when squeezed into a ball. If it doesn’t, it’s best to wait until it dries out to avoid ruining the soil’s structure.
Continue to plant new perennials, ornamental grasses, and roses in beds and containers
If plant roots are pot-bound (encircling the inside of the container), it may be necessary to use a tool to loosen the rootball and flare the roots outward before planting.
Water for the birds
Provide a gentle water drip for migrating birds. The May migrants—warblers, tanagers, orioles, and buntings—are attracted to shallow pools and the slight pinging sound of dripping water.
Annual and Perennial Care
Outdoor Container Care
Fruit, Vegetable, and Herb Care
Tree and Shrub Care
May is a great month to …
build a bee house
Pollinators play a crucial role in our ecosystem, and their numbers are dwindling. Creating a “bee condo” can help some hard-working pollinators, such as native mason bees, find shelter from the elements and build nests. Bee houses with different-sized holes will encourage species diversity, too.