To-Do List: Rocky Mountains

R. L. Rhodes
Print Friendly

THD-pink-geranium-blooms-560x300

Look out! Here comes summer! Springs are so short in our area that we suddenly find ourselves gardening in full swing. Let’s get growing!

  • Water perennials, the lawn and vegetables. Soils dry rapidly during summer, so pay attention to irrigation. In some areas and soils you may need to apply as much as 2 inches of water per week (about 1,200 gallons per 1,000 square feet), less if you mulch. Monitor water needs closely and water the garden in the morning with soaker hoses if possible.
  • Fertilize plants. Side-dress long season vegetable crops, such as tomatoes and corn, with a complete fertilizer when the plants are about one third of the way to harvest, or about one month after planting. Fertilize warm season lawn grasses with no more than a half-pound of actual nitrogen per 1,000 square feet. Do not fertilize cool season lawn grasses in summer unless you intend to irrigate heavily all season long.
  • Pruning and pinch shrubs and perennials to encourage full growth. Prune spring flowering shrubs (those that bloom with or before the common purple lilac) right after they’re finished blooming. Lateral flower buds of peonies don’t amount to much, so pinch them off when they are the size of buckshot, or as soon as they are large enough to pinch. Pinch annuals you want as bushy plants, such as zinnias, petunias, and salvia. Trim hedges before new growth hardens.
  • Watch for insect pests on evergreens. The small (false) cones on the tips of spruce shoots are the plant’s reaction to an insect (Cooley spruce gall adelgid) that usually causes cosmetic damage only. Pick them off or use a soil drench with the insecticide ingredient imadacloprid. To keep mugo pines in bounds, remove 1/3 of new growth on each branch tip. Large, orange, gelatinous masses at the ends of juniper branches following a wet period are signs of the Gymnosporangium fungus, the juniper stage of cedar apple rust. The fungus causes cosmetic damage only, so simply pick them off as they appear.
  • Plant tender bulbs. Now is the time to plant Tigridia, Galtonia, Tritonia, Gladiolus, Anemone, Ismene, and Kniphofia when soil temperature at 4” deep reaches 65 degrees F. Divide clumps of narcissus, hyacinths, tulips, and other spring flowering bulbs right after flowering. After replanting, keep them watered and fertilize with liquid fertilizer.
  • Harvest fruits and vegetables. Remove bird protection netting and harvest fully red-ripe strawberries, as they do not continue to ripen off the plant. Continue to harvest asparagus but leave the last spears to develop into tops to replenish crown strength. Cut asparagus spears while the bracts are tightly closed and there is little purple coloration (except for purple asparagus). Harvest radishes when they are young and tender. Transplant non dormant trees and shrubs (containers only).
  • Plant summer annuals. Add color by planting warm-weather annual flowers like marigolds, zinnias, petunias, salvia, impatiens, begonias, geraniums and coleus.

Got questions about this article or any other garden topic? Go here now to post your gardening ideas, questions, kudos or complaints. We have gardening experts standing by to help you!