Mother Nature seems determined to challenge us. Last year, we were dealing with severe drought, and this year, April brought an over abundance of rain coupled with drastically fluctuating temperatures.
Many of our spring garden activities had to be postponed until our landscapes dried out completely. As you read this May checklist, please realize that you may have to make adjustments based on the environmental conditions at the time.
Woody plant care
In May, trees and shrubs can be planted. Cloudy day planting will help avoid transplant shock. Maintain a consistent watering program of at least 1 inch of water a week on new transplants.
Shrubs that appreciate spring pruning include azaleas, rhododendrons, lilacs, forsythia, viburnums and small magnolias. These shrubs should be pruned immediately after flowering. Remove only one-third of the branches.
Roses in containers can be planted this month. Fertilize roses in May with a 20-20-20 rose fertilizer. In a wet season, monitor your roses for black spot. If spraying becomes necessary, it is recommended to wait for leaves to dry completely before spraying.
Annual and perennial care
It is important to remember that the last frost date for northern Illinois is May 15.
Hardy annuals can be planted mid-month, but tender annuals should not be planted until around Memorial Day. Consider trying some of the many new varieties of annuals that are available this year.
Existing perennials in your garden should be checked as many of them could have had a tough time surviving last year’s drought conditions. They may need a little extra TLC to regain their previous growth pattern.
Summer and fall flowering bulbs can be planted this month.
Lawns should be mowed at 2 to 2 1/2 inches. Grass clippings can be left on the lawn to deliver nutrients to the soil. Fertilize your lawn in the spring only if problems are occurring. The best time to fertilize is in the fall. A pre-emergent weed killer application will mean that you can not put grass seed in that area.
Fruit and vegetable gardening
Eastern tent caterpillar could appear on crabapples and other flowering fruit trees. Remove entire tent structure and burn it.
Vegetables that can be planted in mid-May include corn, snap beans, summer squash and spinach.
Aged compost applied to your garden will enhance the growth in both vegetable and herb beds.
Indoor plant care
Indoor houseplants can gradually be moved outside to protected areas away from windy locations and too much sun exposure to afternoon sun. Temperatures below 55 degrees will be damaging to houseplants.
“Gardening smart” can be accomplished in our landscapes by planning ahead. We have had a very wet start to the spring season. If this continues, our plants will thrive, but so will the insect population. It will be important to encourage the beneficial insects as they strive to reduce the population of damaging insects.
Recent information from Candice Miller, University of Illinois horticulture educator, provides some great advice on how to encourage beneficial insects to take up residence in your garden. Plant a variety of flowers, fruits and vegetables. Think about planting sweet alyssum, Queen Anne’s lace, and in the herb family, small flowered dill, fennel and coriander to attract beneficial insects.
• The Master Gardeners are available to answer questions from 9 a.m. to noon Monday to Friday at the University of Illinois Extension DeKalb County office in the Farm Bureau Center for Agriculture, 1350 W. Prairie Drive, Sycamore. Walk-ins are welcome. For information, call 815-758-8194 or email DeKalb_mg@extension.uiuc.edu.