May is the month when we really can’t wait to get our gardens started. Everywhere we go, there are temptations. Great plant sales are being advertised, and they are hard to resist. It is wise to keep in mind that the last frost date for northern Illinois is May 15. A little caution and patience is often necessary. Many of the cold-sensitive flowers and vegetables are best planted from mid-May to late May.
Woody plant care
Larger plants like trees and shrubs can still be planted this month with transplants needing a thorough watering at planting time and at least one inch of water a week for the first year.
May is a good pruning time for spring-flowering shrubs and trees. Pruning should take place as soon as blooming is finished to maintain good health and appearance.
After removing dead, damaged or diseased portions of the plants, thinning or heading are two pruning techniques that you can use to open up the center of plants to create better sun exposure and air circulation.
Roses can be fertilized this month with a 20-20-20 solution as soon as buds are set. Monitor succulent new growth on roses as aphids may appear. Spray with a strong stream of water to remove this pest.
Annual and perennial care
Hardy annuals can be planted early this month, but cold-sensitive annuals will do better if planted mid to late May. Harden off newly purchased annuals prior to planting. To encourage an abundant growth habit, pinch back one-third of the new growth. It is hard to give up those first new flowers, but this technique really works. (Do not pinch back vines.)
New perennials, ornamental grasses and roses purchased in containers may be root bound (encircling the pot). When this happens, make four cuts into the bottom of the root ball with a sharp tool and flare the sections outward when planting.
Emerging oriental lily shoots can be treated with an anti-rodent spray if rabbits and deer have been a problem.
When planning your containers, succulents should be considered as they are tolerant of hot, dry conditions and will require less water during the hotter parts of the summer.
Our lawns often are the area most used for social activities. Proper lawn care will keep them in good condition. In May, mow lawns at 2 to 2½ inches and leave clippings to return nutrients to the soil.
Fruit and vegetable care
Mid-May is a good time for planting corn, snap beans and summer squash.
Carrots, beets and late lettuce should be thinned.
Asparagus and rhubarb should be ready for harvest this month.
The interplanting of edibles and ornamentals has been a popular trend recently. This combination can be an attractive and functional new feature for your garden.
One of the greatest joys in early spring is the return of the birds from their winter habitats. At our home, barn doors are opened early as we look forward to the return of the swallows. By summer, three families are busy raising their young.
Other birds will be returning as well and looking for a good habitat environment. As gardeners, we can help the birds by providing good food sources, especially native plants, nesting sites, shelter and water. Water is the most overlooked necessity for birds. Water can easily be provided by supplying a birdbath or a simple system that drips water.
May is here and the gardening season has finally arrived. Enjoy your 2017 gardening season.
• The Master Gardeners are available to answer your questions from 9 a.m. to noon Monday through Friday at the University of Illinois Extension DeKalb County office location in the Farm Bureau Center for Agriculture, 1350 W. Prairie Drive in Sycamore. Call 915-758-8184 or email firstname.lastname@example.org. Walk-ins welcome.