How to add color to your early spring garden
We’ve reached the point in spring when you might want to plant cool-season annuals that can tolerate a light frost, like pansies and primulas, to add color to your early spring garden. Other annuals sold for spring are good to use too, but not as tolerant of very cold weather, so they’ll benefit from a slightly later planting date or protection during cold nights.
Just keep in mind that you might want to install your annuals a bit later if unusually cold weather is in the forecast. Temperatures that drop into the low 20s Fahrenheit can damage even cold-tolerant annuals like pansies, and temperatures that go down to 25 degrees will likely damage the flowers on pansies — the plants should survive, but the exposure will limit their spring flower display.
These early spring annuals can be planted under bulbs to complement their flowers and extend spring color until summer annuals are ready to plant in mid-to-late May. Choose plants that are well developed, with lots of flowers and buds, since cool season annuals don’t have much time to develop after planting. If we see an exceptionally cold night with temperatures below 28 degrees, it’s a good idea to cover these plants.
If you’re planting any bare root material this spring, plant it as soon as you can after it arrives in the mail. When you unpack plants, make sure the packing around their roots is moist, and store the plants in a cool place that won’t freeze until they can be planted. It’s always a good idea to soak the roots of trees and shrubs in water for a short period of time before planting. You don’t want the roots to dry out! You only need to prune broken branches and roots before planting — no need to prune to compensate for transplant shock.
Also in mid-April, before the weeds start to germinate, apply crabgrass control to your lawn if you had problems with crabgrass last year; if you didn’t have an issue last year, there’s no need. Most of the products available provide control by stopping the seeds from germinating for about 60 days; crabgrass is an annual weed, and it germinates after soil temperatures are greater than 55 degrees Fahrenheit for five to seven days — so you’ll want to apply crabgrass control products before plants like lilacs and redbuds begin to flower.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.