As hot July weather settles in, we are lucky to have had frequent rain during the spring and early summer. Our plants are displaying lush growth and producing an abundance of flowers. With temperatures rising, our plants will require more frequent watering and some fertilizing to help them maintain their current healthy appearance.
Woody plant care
Newly planted or transplanted trees, shrubs and roses will need 1 inch of water per week to get moisture to their root zones.
Hot weather will push weed growth. So, we will need to continue to cultivate weeds around our trees and shrubs.
If your forsythia, red-twig dogwood or lilac bushes have become overgrown, they can be renovated by removing one-third of the oldest canes.
Mulching is very beneficial to trees and shrubs during the summer months.
Roses may be showing signs of blackspot. If rose leaves are displaying yellow foliage with dark spots, they have blackspot. These leaves should be removed from the plant and the rose garden area. In the future, choose disease-resistant rose varieties.
Deadhead roses this month as blooms fade.
Fertilize roses this month with a 20-20-20 fertilizer. This is the final treatment for the year. Do not fertilize roses after Aug. 1.
Annual and perennial care
Annuals that are densely planted should be monitored for fungal diseases that may occur as a result of the damp weather earlier this season.
Remember that annuals in containers and hanging baskets will need frequent watering during hot and windy weather.
As Oriental poppies fade out in midsummer, annuals and later-blooming perennials can be planted in front of them.
If you have tall perennials in a windy location, they will benefit from loose staking with soft ties.
Daylily seed heads and spent flowers should be removed immediately to conserve energy for the plant.
Turf grass may go dormant as temperatures increase. The crown will remain alive as long as your grass receives 1 inch of water a week.
Mowing your lawn at a high level in summer is a good idea. A level of 2½ to 3 inches is recommended.
July is not a good time to apply either herbicide or fertilizer to your lawn.
Herb, fruit and vegetable care
Pinch off flowers on your herbs to retain flavor and essential oils. Harvest and use your herbs fresh or dry them for future use.
Caterpillars that eventually turn into swallowtail butterflies may be evident on your fennel, dill and carrot plants.
Hand pick and remove hornworms found on your tomato plants.
Seeds for fall crops can be sown in late July. Seeds to consider include cool-season lettuces, cabbage, beans, spinach and broccoli.
Many tropical vines are very happy to be a part of your summer garden. Vines for hot weather include mandevilla, bougainvilla, passion flower and clerdendrum bleeding heart. These tropical vines produce spectacular flower displays and are available at most large garden centers.
All of these vines prefer a sunny location and soil high in organic material.
A big plus with all of these vines is that they can be easily overwintered and brought back out for another season of bloom in the spring. Check the University of Illinois website for specific details on overwintering these vines. In an article titled “Hot Vines” by horticulturist Greg Stack, you will find specific guidelines for safely getting these beautiful vines through the winter months.
Consider adding some of these hot vines to your summer garden for a unique tropical flair.
• The Master Gardeners are available to answer questions from 9 a.m. to noon Monday through Friday at the University of Illinois Extension DeKalb County office in the Farm Bureau Center for Agriculture, 1350 E. Prairie Drive in Sycamore. Call 815-758-8194 or email firstname.lastname@example.org.