Spring garden tasks for healthy plant growth
This is a great time of year to be outside working in the garden, though the weather can prove challenging at times — the last couple of rainy Sundays have definitely impacted my ability to do garden maintenance at home.
Still, I try to squeeze in some time to finish cutting back perennials and cleaning up garden debris as the weather permits. It is best to cut perennials back before they start growing to minimize any possible damage to the new growth. Most perennials have started to grow by now, so just be mindful of the new growth as you work in the garden. You’ll want to stay out of garden beds when soil conditions are wet to avoid compacting the soil.
It can be hard to see the new growth on some ornamental grasses. Warm season grasses will start growing when weather conditions become more consistently warmer. If you’re unsure of how aggressively to cut the grasses back in your garden, cut them back at a few inches above the ground to avoid the new shoots. Be careful of any bulbs that may have started growing.
Begin uncovering hybrid roses around the middle of April by carefully removing mulch from the base. Wait a bit later if excessively cold temperatures are predicted, and uncover earlier if the weather is forecast to be consistently warm. A bamboo stake works well for this task. Leave a small amount of mulch at the base of the plant for protection in case of a late hard freeze. Prune these roses back to live growth, indicated by green stems, which in some years may leave only 1 to 2 inches of stem after you finish pruning. I’ve been observing a lot of winter damage so far this spring.
For bare root plant materials, install them as soon as possible after they arrive in the mail. Unpack plants and make sure the packing around the roots is moist. Store the plants in a cool place that will not freeze until they can be planted. It helps to soak the roots of trees and shrubs in water for a short period of time before planting. Don’t let the roots dry out! You only need to prune broken branches and roots before planting; there’s no need to prune to compensate for transplant shock.
Most perennials are best divided in spring when they are showing a couple inches of growth. When dividing a plant, choose the strongest looking parts of the plant and discard the rest. A sharp, flat garden spade works best for this job. Plants that bloom in April and May can also be divided after they bloom.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.