Weather in May can be volatile, so stay aware of the forecast.
Although the average last frost (32 degrees) in Colorado Springs occurs May 10-15, it’s not unusual to have a hard freeze (28 degrees) late in the month.
Here’s a checklist for gardeners:
• Clean and sharpen garden tools.
• Change oil in lawnmower, sharpen the blade and replace the air filter, if needed.
• To eliminate the transfer of disease, clean potting containers with a solution of one part bleach to 10 parts water.
If you had diseased containers last year, do not reuse soil. Otherwise, renew soil by removing at least 10% of the soil and adding compost.
• Remove faded flowers from spring bulbs, but don’t remove leaves until they have yellowed because they provide energy for next year’s blooms.
• Start feeding roses a balanced rose food every six weeks.
• Begin planting gladiolus every two weeks mid-May through June for a series of blooms.
• Stake peonies and delphiniums.
• After the danger of frost has passed, begin planting tender annuals.
• Plant annual seeds outdoors mid-May.
• To maintain a healthy lawn, fertilize late in May or early in June using a fertilizer with high nitrogen content for a quick boost.
• Check your irrigation system to ensure it’s reaching all areas of the lawn and gardens.
• Seed any dead or bare areas of the lawn.
Trees, shrubs, perennials
• Prune early spring flowering trees and shrubs such as lilacs and forsythia after flowers fade.
• Begin to prune many evergreens and conifers.
• Plant container-grown and balled and burlap trees and landscape shrubs.
• Plant raspberries, blackberries and potted roses.
If you’re not sure what will grow in this region, look for perennials marked “Plant Select.” These plants will thrive in the tough climate.
• On warm days, a week or two before planting, begin hardening off seedlings in a sheltered location starting with 15 minutes a day and increasing daily by 15-minute increments.
• Thin seedlings of early planted crops such as carrots, lettuce, spinach and beets.
• Asparagus stalks can be harvested at soil level when they are larger than 3/8-inch diameter, as long as they are 3 years old.
Late May when soil is as least 50 degrees:
• Transplant tomatoes and bury them deep to the top most pair of leaves so they will root all along their stems.
• Plant eggplant and pepper plants.
• Plant corn, bean, pumpkin, squash, cucumber and early-maturing melon seeds.
Submit gardening questions to email@example.com. The in-person help desk will open 9 a.m. to noon and 1-4 p.m. May 19 and 26 at 17 N. Spruce St. Call 719-520-7684.