Tidewater Gardening - August 2009
K. Marc Teffeau
August is the time for vacations, relaxing and, if you have school-aged children, getting ready for the new school year. With other things occupying our interests, the garden and landscape sometimes take a back seat. This is OK. With the hot, muggy August weather it is sometimes hard to get motivated. But, lest you think that gardening activities also take a vacation, there are still some jobs to be done.
A major focus is on correct watering. Unless you have been blessed with periodic thunderstorms dumping rain on your landscape, many plants need extra irrigation. Vegetable gardens, most flowering plants and the lawn all need about one inch of water very week to keep them green and looking nice.
Be sure to water thoroughly and deeply each time you water. When possible, do your watering in the morning or early afternoon so the soil has a chance to warm up before the cooler evening hours set in. Deep watering will induce the plant’s roots to grow deeper where they are less likely to dry out. That also has the added benefit of anchoring the plant into the ground better. This deal about going out with the hose and spraying everything for 10 minutes really does not do the job.
A light surface watering actually wastes water because the water never reaches the root zone of the plant, and the moisture rapidly evaporates from the top inch of soil. The best way to tell if your plants are receiving enough water is to take a trowel or shovel and dig down a few inches. The soil should be moist at least 3 to 4 inches deep to insure that the water is reaching the root zone of the plants.
It’s not too late to check the garden supply stores to see if they have end-of-the-season sales on soaker hoses. Soaker hoses are an inexpensive way to provide the deep irrigation needed for the garden and landscape to flourish.
Remember to check your hanging baskets and your container flowers and vegetables. They can be easy to forget when its watering time. Push your finger an inch or two into the soil to be sure there is adequate moisture throughout the root area. Water them thoroughly each time you water, but be careful not to over water.
August is not the time to prune ornamental trees and shrubs. The removal of large branches, unless they are dead, at this time of year will tend to stimulate new branch growth. Because of their late start, these new branches will not be able to acclimate themselves before the first frost and subsequent cold weather. The results will be winter injury and dying of these new branches, as well as injury to the entire plant.
If you did not get around to pruning your woody plants this spring or early summer, forget about them until next march or April. Definitely do not prune spring flowering shrubs. Pruning them at this late date will remove the flower buds for next year.
On the other hand, if your hedge is beginning to look a little shaggy, there is still time left to do light summer pruning or shearing. Also, if you did not get around to it earlier in the summer, you can still deadhead old flower seed heads of lilac and crepe myrtle.
Now is also not the time to do any extensive fertilizing of the trees and shrubs in the landscape. Like late-season pruning, late-summer fertilizing will stimulate growth which will be soft and easily killed by the first frost.
In addition to producing soft growth, fertilizing now can also stimulate the plants into growth if we have an Indian summer later this fall. If this happens you can almost guarantee that your plants will not be able to survive the winter. If you neglected to fertilize your trees and shrubs this past spring, continue to neglect them until sometime around the first of November, or after the first or second hard frost.
Annual and perennial flower beds tend to look a little raggedy at this time. Pick off the old dead flowers on your annuals, as well as the spent flowers and flower stalks of perennial plants. A little time spent on grooming the plants will make a big difference in the overall appearance of the garden. By removing the spent flowers, the plants will not go into the seed-producing stage and should continue to flower longer into the season.
Fall-blooming crocus should be planted this month to give you an extra week or two of flowers after the main garden plants have finished for the year. Spring-flowering perennials can be divided and transplanted this month or next. Be sure to do this during the coolest part of the day and water the plants thoroughly after transplanting.
Make sure to prune your hybrid roses in late August to promote the most fall blooms. Remove about a third of the vigorous growth. Any stems that cross each other should be removed, as well as those that are in the center of the plant. Weak, spindly canes and any damaged by black spot fungus should be removed.
Maintain a spraying schedule to control insects and diseases. Clean up fallen rose leaves. They can harbor disease and insect pests over the winter if allowed to remain on the ground.
Now is the time to plant fall and winter vegetables in the vegetable garden. Plant starters or seeds of green onions, carrots, beets, lettuce, spinach and radishes. You can also plant transplants of fall broccoli, cabbage and Brussels sprouts. Water the plants with a weak liquid fertilizer solution and water. This will help them get a jump start.
Pinch off onion flower buds from the top of the plants to direct all of the plant’s energy into the developing bulb instead of seed production. Many herbs have a tendency to self sow if the flowers are not removed. Dill produces seeds that fall around the parent plant and come up as volunteers.
Powdery mildew affects a number of ornamental plants in the landscape including lilacs and annual flowers at this time of year. This disease occurs on plants when the days are hot and the nights cool. Growing mildew resistant cultivars of plants is your first line of defense. Good culture and sanitation are also important for control. Avoid use of a high nitrogen fertilizer at this time of year as it promotes lush foliage which is very mildew susceptible. Treat the plants with a fungicide on an as-needed basis.