Tidewater Gardening - June 2012

Early Summer Garden Chores
by
K. Marc Teffeau

Early summer is a busy time for home gardeners. By now you’ve probably got most of your first plantings of vegetables and flowers done, but there are still a number of chores awaiting you. Don’t forget about your spring flowering bulbs. Now that the flowers are faded memories it is time to provide them with a little care to ensure a good flower display next spring.
Leave the foliage on the bulbs until it starts to brown. Top dress the bulbs with bone meal or some 5-10-5 fertilizer to help the bulbs store up food reserves for next year. If your bulb planting seems to have been declining in flower production, maybe you need to thin and replant this fall. Make a note on the home calendar to do this.
There are some shrub and tree pruning jobs that you can do in June. Pruning now involves cutting back the rampant growth that many trees and shrubs made during the spring season. You can head back and thin over-vigorous shrubs to the desired size in the landscape.
Cuts on trees and shrubs made at this time will heal quickly. Do not cover the pruning wounds with pruning paint. This is no longer a recommended practice.
While you are at it, be sure to remove the old seed heads of lilacs and rhododendrons by hand. Do this now to increase growth and the development of flower buds for next year; you want the plant’s energy to go into maintaining the plant and not producing seeds.
Pruning on spring flowering shrubs should be done now because if you prune in late August you will prune out the flowering wood and buds for next year.
Shrubs and trees that provide color in the month of June include late-blooming azaleas, hydrangeas, rhododendrons, spireas, butterfly bush, mock orange and golden rain tree. Planting woody perennials in June will require a little extra attention, especially when we get into dry spells, but the effort is well worth it.
Using gator bags is a great way to keep trees watered during hot dry months. These bags, which hold up to 20 gallons of water, are secured to the trunk of the tree where they release the water slowly to the root ball over the course of 15 to 20 hours.
Don’t forget that you can always do additional plantings of annuals and perennials at this time. The garden centers have many beautiful annuals to choose from including geraniums, impatiens, marigolds, petunias, vinca and salvia. Perennials that provide interest in the month of June include daylilies, astilbe, rudbeckia, yarrow, foxglove and heuchera.
I like to recommend fertilizing annuals, perennials and flowering shrubs and trees with a slow-release plant food that contains nitrogen, sulfate of potash, iron and other micro-nutrients for overall plant growth and development.
June is the time to divide and replant German iris. Cut back the leaves and divide the clumps into single plants with one of two sections of healthy rhizome. Discard any diseased plants. If disease has been a problem with your iris, it may be wise to try a new location in the landscape.
You can move houseplants outside to the deck or patio and enjoy them outdoors for the summer. It is best to gradually introduce them to more direct sunlight to prevent the leaves from burning. Feed houseplants with the good quality indoor plant food, either in the liquid form or as one of the CRF’s (controlled release fertilizers) that are available at garden centers or retail stores.
Pinch and shape the plants as they grow to produce nice symmetrical full plants to bring back into the house next fall. Be sure to keep the insects under control so you don’t bring them into the house in the fall with the plants.
This is also the time to re-pot root-bound houseplants to larger pots, if needed. Use a potting mix specifically formulated for houseplants when you do the repotting.
Along with putting your houseplants on the deck, look for plants that can add color to the patio and deck. Hibiscus, jasmine, oleander and mandevilla are just some of the flowering tropical plants you can add to provide color.
Weed control in June is very important in the vegetable garden and landscape. Even if you haven’t mulched your plants, it’s not too late. Clean up the bed of existing weeds. If you use a hoe, be sure not to cultivate too deeply around shallow-rooted plants. This is a good place to use a swan-neck scuffle or rocker hoe, as this tool does not penetrate the soil deeply. Azaleas and boxwood are two shrubs especially vulnerable to careless cultivation.
Do not mulch too deeply, either. Two inches is adequate in the landscape. Over-mulching is one of the main causes of death of plants in the landscape.
Traditional roses have already reached their peak bloom. To make sure that they continue to bloom all summer, keep to a regular spray schedule. Also, break off old blooms as soon as the petals drop. Roses should be ready for a light application of a balanced fertilizer now that their first blooming period is coming to an end.
With all the organic matter now produced in the landscape, don’t forget about the compost pile. Grass clippings, weeds and any other organic refuse will decompose rapidly in a compost pile during the warm summer months. To speed up decomposition, shred the organic material as fine as possible, add a thin layer of soil, some lime and high nitrogen fertilizer and keep the pile moist. Turn the pile every couple of weeks to help the process along. There are a number of different types of composting bins and tons of information on the Web regarding proper composting.
Homeowners may notice odd growths on tree leaves this time of year. When I was the Extension Agent for Talbot County I used to receive lots of calls and samples about odd structures that homeowners found in their trees. Many home gardeners have discovered lumpy protrusions or galls which form on the branches, twigs and leaves of certain trees and shrubs.
Most of these galls result from the activity of tiny insects and mites that “sting” the branch, twig or leaf surface. The sting of the insect is actually the depositing of eggs in the plant tissue. The galls that form safely house the developing insects or mites as they feed on the host plants.
The gall formation process is not completely understood, but it seems that the egg or the stinging process applies an enzyme that the plant cells react to. The size and shape of the gall is characteristic of the insect specie that produces it. Galls vary in appearance from small pimple-like projects on leaves, to relatively large swellings such as the familiar golf-ball-sized “apple” sometimes seen on oak trees.
Several types of insects are responsible for galls on your landscape plants. For example, most oak galls are caused by small wasps. Aphids produce spruce galls. The dogwood club-gall is formed by a tiny fly. And a mite causes maple bladder gall, that frequently affects certain species of maples.
Control for these gall-makers is often difficult. Where practical, prune out and destroy the galls. I haven’t seen the galls actually kill a plant, but it might make it so unattractive that it loses its landscape value. Spraying is usually not recommended, especially on the oak galls as timing of the spray is almost impossible. Fertilize infected plants to encourage new growth.
Sometimes galls are caused by bacteria or fungi. Common examples include cedar-apple gall on red cedar, crown gall on roses and exobasidium leaf gall on azaleas. These galls are best controlled by removing and destroying them.
Happy Gardening!