2 July 2007
Virginia Cooperative Extension, Charlottesville/Albemarle County Office
460 Stagecoach Road, Charlottesville, Virginia 22902
phone: 434.872.4580 fax: 434.872.4578
We had some great weather for gardening this past weekend but many areas are behind on their rain requirements. Keep up as best you can, use drip irrigation where possible and slow release water sources on specific larger plants. Newly planted trees and shrubs are the most susceptible. As the summer heats up there are plenty of other activities to keep your landscape attractive and healthy. Here are a few to think about.
Take a look around your landscape to see what is working and what is not. If there are plants that have outgrown their space, need to be divided or moved, flag them now so you will remember to do something about it this fall.
Replace leggy or spent annuals with drought tolerant plants such as salvia, portulaca, and melampodium.
Divide hostas anytime before fall but the best time is after flowering. Pinch back chrysanthemums and asters.
Water and mulch your azaleas, rhododendrons, and camellias as they are producing buds for next year.
Protecting your dogwoods from drought stress can go a long way toward keeping them healthy. Make sure they have been mulched in a wide ring with organic material, about 3 inches deep (do not use dogwood leaves or wood as mulch, and pull back from trunk). During prolonged dry periods, water dogwoods thoroughly.
Some tree companies shred their trimmings on site and give them away free-for-the-asking to anyone in the neighborhood. Do not be shy! Your use of the chips keeps them out of the local landfill.
When drought hits, if you cannot water rose bushes, do nothing else. Fertilizing, pruning, applying pesticides, or even cutting flowers can harm plants that are water-stressed
Prune big leaf or French Hydrangeas (H. macrophylla), those with large, pink or blue "snowball" flowers, immediately after flowering.
Tip dieback of redbud (Cercis canadensis) may be caused by saturated soil. Redbuds are very intolerant of "wet feet" caused by prolonged wet soil and high humidity.
Some woody ornamentals attractive to hummingbirds are crabapple, hawthorn, Albizia, Siberian pea shrub, tulip tree, buckeye, and horse chestnut.
University of California research showed that newly planted shrubs watered every few days outgrew shrubs watered every 10 to 12 days by almost five times. Once they are established one good soak per week is sufficient.
When pruning away twiggy young growth from rose bushes, make use of the cuttings by rooting them and producing new plants. Treat stem bases with rooting hormone, stick them in soil in a cold frame that is out of the sun and water them well. Keep them watered. If some die before rooting, it's no great loss. Just toss them in the compost, which is where they would have ended up anyway.
Root holly, azalea, and camellia cuttings in a sand and peat moss mixture set in a cool, shady location. Ivy and periwinkle can be rooted now to fill in any bare spots in your beds. Do not allow cuttings to dry out.
During dry spells, trees may shed up to 10 percent of their leaves. This leaf loss reduces water losses through transpiration and causes little or no harm to the tree.
Inner leaves and twigs of trees normally drop from lack of sunlight, but falling clusters of leaves attached to short twigs may result from insect or squirrel activity. Girdling insects make shallow, encircling depressions, while twigs broken by squirrels have diagonally severed ends.
During hot, July weather, be sure to mow your lawn to the appropriate height. This reduces water loss and helps lower soil temperatures. Leave clippings on the lawn to decompose.
Observe the lawn area and the shade it receives. Plan to thin major shade trees next spring to increase light reaching patchy turf.
Proper watering means deep soaking. Light sprinkling is often harmful. Wet the soil to the bottom of the roots (4 to 6 inches deep).
Dull or improperly adjusted mower blades that shred grass rather than cut it can cause a brown or grayish cast over lawns. Sharpen your mower blades at least once a year.
When mowing your lawn, watch out for your trees and shrubs. Lawn mower and weed whacker injury to trees opens wounds that make trees and shrubs more susceptible to insects and diseases.
For more information about this and other landscape topics contact your local Virginia Cooperative Extension office. The local Virginia Cooperative Extension office numbers are Albemarle 872-4580, Fluvanna 591-1950, Greene 985-5236, Louisa 540-967-3422, and Nelson 263-4035.