June Gardening Calendar

Published: May 16, 2017

Ornamentals

• Week 1: Deadhead bulbs and spring flowering perennials as blossoms fade.
• Week 1: Watch for bagworms feeding on many garden plants, but especially juniper and arborvitae.
• Week 1: Thin seedlings to proper spacings before plants crowd each other.
• Weeks 2-4: Plant tropical water lilies when water temperatures rise above 70 degrees.
• Weeks 2-3: When night temperatures stay above 50 degrees, bring houseplants outdoors for the summer.
• Weeks 2-3: Apply a balanced rose fertilizer after the first show of blooms is past.
• Weeks 2-3: Rhizomatous begonias are not just for shade. Many varieties, especially those with bronze foliage, do well in full sun if given plenty of water and a well-drained site.
• Weeks 2-3: Most houseplants brought outside prefer a bright spot shaded from afternoon sun. Check soil moisture daily during hot weather.
• Weeks 2-3: Apply organic mulches as the soil warms. These will conserve moisture, discourage weeds, and enrich the soil as they decay.
• Weeks 2-3: Apply a second spray for borer control on hardwood trees.
• Weeks 3-4: Softwood cuttings can be taken from trees and shrubs as the spring flush of growth is beginning to mature.
• Weeks 3-4: Continue spraying roses with a fungicide to prevent black spot disease.
• Weeks 3-4: Tired of the same old foundation plantings? Find fresh ideas among the evergreens planted in the Dwarf Conifer collection.
• Weeks 3-4: Trees and shrubs may still be fertilized before July 4th.
• Weeks 3-4: Pruning of spring flowering trees and shrubs should be completed before the month's end.

Lawns

• Weeks 1-4: Water turf as needed to prevent drought stress.
• Weeks 1-4: Mow lawns frequently enough to remove no more than one-third the total height per mowing. There is no need to remove clippings unless excessive.
• Weeks 1-4: Gradually increase the mowing height of zoysia lawns throughout the summer. By September, the mowing height should be 2 to 2.5 inches.
• Weeks 1-4: Mow bluegrass at 2 to 3.5 inch height. Turfgrasses growing in shaded conditions should be mowed at the higher recommendations.
• Weeks 1-2: Zoysia can be fertilized now while actively growing. Do not exceed 2-3 pounds of actual nitrogen fertilizer per l000 sq. ft. per year.

Vegetables

• Weeks 1-2: Repeat plantings of corn and beans to extend the harvest season.
• Weeks 1-2: Plant pumpkins now to have Jack-o-lanterns for Halloween.
• Weeks 1-2: As soon as cucumber and squash vines start to 'run,' begin spray treatments to control cucumber beetles and squash vine borers.
• Weeks 2-4: Set out transplants of Brussels sprouts started last month. These will mature for a fall harvest.
• Weeks 2-4: Soaker hoses and drip irrigation systems make the most efficient use of water during dry times.
• Weeks 2-4: To minimize diseases, water with overhead irrigation early enough in the day to allow the foliage to dry before nightfall.
• Weeks 2-3: Start seedlings of broccoli, cabbage and cauliflower. These will provide transplants for the fall garden.
• Week 2: Stop harvesting asparagus when the spears become thin.
• Weeks 3-4: Control corn earworms. Apply several drops of mineral oil every 3 to 7 days once silks appear. Sprays of Bt are also effective.
• Week 3: To maximize top growth on asparagus, apply 2 pounds of 12-12-12 fertilizer per l00 sq. ft., water well and renew mulches to conserve moisture.

Fruits

• Week 1: Oriental fruit moths emerge. They are most serious on peaches where the first generation attacks growing tips. Wilted shoots should be pruned out.
• Week 1: Thinning overloaded fruit trees will result in larger and healthier fruits at harvest time. Thinned fruits should be a hands-width apart.
• Week 1: Enjoy the strawberry harvest.
• Weeks 2-3: Renovate strawberries after harvest. Mow the rows; thin out excess plants; remove weeds; fertilize and apply a mulch for weed control.
• Weeks 2-3: Summer fruiting raspberries are ripening now.
• Weeks 2-3: Begin control for apple maggot flies. Red painted balls that have been coated with tanglefoot may be hung in apple trees to trap egg-laying females.
• Weeks 2-3: Spray trunks of peach trees and other stone fruits for peach tree borers.
• Weeks 3-4: Prune and train young fruit trees to eliminate poorly positioned branches and to establish proper crotch angles.

Miscellaneous

• Weeks 3-4: When using any gas powered equipment, be sure to allow the engine a few minutes to cool before refilling empty fuel tanks.
• Weeks 3-4: A mailbox mounted on a nearby post makes a handy place to store and keep dry any small tools, seeds, labels, etc. frequently used in the garden.

Gardening Calendar supplied by the staff of the William T. Kemper Center for Home Gardening located at the Missouri Botanical Garden in St. Louis, Missouri. (www.GardeningHelp.org)