July Gardening Calendar

Published: June 19, 2019

Ornamentals

• Provide water in the garden for the birds, especially during dry weather.
• Remove infected leaves from roses. Pick up fallen leaves. Continue fungicidal sprays as needed.
• While spraying roses with fungicides, mix extra and spray hardy phlox to prevent powdery mildew.
• Newly planted trees and shrubs should continue to be watered thoroughly, once a week.
• Fertilize container plants every 2 weeks with a water soluble solution.
• Keep weeds from making seeds now. This will mean less weeding next year.
• Keep deadheading spent annual flowers for continued bloom.
• Perennials that have finished blooming should be deadheaded. Cut back the foliage some to encourage tidier appearance.
• Plant zinnia seed by July 4th for late bloom in annual border.
• Spray hollies for leaf miner control.
• Prune climbing roses and rambler roses after bloom.
• Apply final treatment for borers on hardwood trees.
• Apply no fertilizers to trees and shrubs after July 4th. Fertilizing late may cause lush growth that is apt to winter kill.
• Hot, dry weather is ideal for spider mite development. With spider mite damage, leaves may be speckled above and yellowed below. Evergreen needles appear dull gray-green to yellow or brown. Damage may be present even before webs are noticed.
• Fall webworms begin nest building near the ends of branches of infested trees. Prune off webs. Spray with Bt if defoliation becomes severe.
• Divide and reset oriental poppies after flowering as the foliage dies.
• Semi-hardwood cuttings of spring flowering shrubs can be made now.
• Summer pruning of shade trees can be done now.
• Powdery mildew is unsightly on lilacs, but rarely harmful. Shrubs grown in full sun are less prone to this disease.
• Divide bearded iris now.
• Don't pinch mums after mid-July or you may delay flowering.

Lawns

• Water frequently enough to prevent wilting. Early morning irrigation allows turf to dry before nightfall and will reduce the chance of disease.
• Monitor lawns for newly hatched white grubs. If damage is occurring, apply appropriate controls, following product label directions.

Vegetables

• Blossom-end rot of tomato and peppers occurs when soil moisture is uneven. Water when soils begin to dry; maintain a 2-3 inch layer of mulch.
• To minimize insect damage to squash and cucumber plants, try covering them with lightweight floating row covers. Remove covers once plants flower.
• Dig potatoes when the tops die. Plant fall potatoes by the 15th.
• For the fall garden, sow seeds of collards, kale, sweet corn and summer squash as earlier crops are harvested.
• Set out broccoli, cabbage, and cauliflower transplants for the fall garden.
• Sweet corn is ripe when the silks turn brown.
• Keep cukes well watered. Drought conditions will cause bitter fruit.
• Harvest onions and garlic when the tops turn brown.
• Sow seeds of carrots, beets, turnips, and winter radish for fall harvest.
• Cover grape clusters loosely with paper sacks to provide some protection from marauding birds.
• Prune out and destroy old fruiting canes of raspberries after harvest is complete.
• Blackberries are ripening now.
• Apply second spray to trunks of peach trees for peach borers.
• Early peach varieties ripen now.
• Thornless blackberries ripen now.

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)