Inquiring Gardeners Want To Know... WHAT ARE SOME GOOD SUMMER WATERING PRACTICES FOR THE LANDSCAPE?

One of the first signs of drought stress in ornamentals and turf is wilting. Many of our favorite plants show drought related symptoms differently. The leaves of some plants may exhibit marginal leaf burn or leaf scorching while others will simply wilt. We've already experienced dry periods in much of NC in April and May. Daily wilting of many spring planted ornamentals has already occurred. These plants will be wilted by mid afternoon on a hot day, but will be completely recovered the next morning after a soaking with the garden hose. An extended period without extra moisture and this temporary wilting can become a permanent, non reversible situation.

This is known as permanent wilting point, and the next step is to remove a dead plant! Leaves wither, and remain on the plant or drop completely. Twig and stem dieback will follow.

There are several plants that are typically grown in many landscapes that we can use as indicator plants. These plants wilt readily and are usually the first ones to show drought stress. They are azaleas, dogwoods, hydrangeas, most annuals and turf.

When these plants begin to look thirsty, you should have a plan to get water to the roots. A hand held hose is probably the fastest plan of action, but we all know that a lot of water is wasted when it is applied this way. Many home gardeners are not patient enough to apply enough water to each plant in order to relieve drought stress. Turn the water on very low and when runoff begins, go to the next plant. When you've finished watering all the individual plants, go back and repeat the process. The additional water will soak in much better this time.

The same strategy is true for the sprinklers. Turn water on and when runoff occurs, move it to another location. Repeat the watering to really saturate the soil.

Remember to build an earthen saucer around individual trees and shrubs to act as a dam for hose applied water. This will reduce the amount of runoff, and also be a much faster way to hand irrigate. Be sure to have a 3” 4” layer of organic mulch on the beds and if you haven't tried it yet, buy a roll of landscape fabric and install it around trees and in beds. This will not only conserve moisture but will also discourage weeds. If you are growing summer color plants in containers, it will be to your advantage...and the plants'…to keep a water saucer under the pot. Pots will not dry out so quickly


JUNE GARDEN CHORES

o Powdery mildew on Crapemyrtles: If you have been paying close attention to your crapemyrtle foliage lately, you've probably noticed that the disease has already started. According to the 2006 Ag. Chemicals Manual, Banner 14.3% or Bayleton 25W are the recommended fungicides. Spraying a few times or seeing the results of doing nothing will make you a true believer in using resistant cultivars. The following are resistant: 'Biloxi,' 'Byers Standard Red,' 'Byers Wonderful White,' 'Miami,' 'Osage,' 'Seminole,' 'Tuscarora,' 'Tuskegee,' 'Yuma' and 'Zuni.'

'Lagerstroemia faurei' is also becoming a popular choice as a mildew resistant crapemyrtle. 'Carolina Beauty' and 'Potomac' are two very popular cultivars that are susceptible to powdery mildew.

o What are your landscape plants telling you? Now is a good time to stroll around the landscape and be observant. Look at the new growth on the trees and shrubs. There should be several inches on the ends of the branches. (The new growth generally follows flowering on spring flowering plants.) This growth is an "indicator of progress." Also look at the tops of old shade trees in the yard. There should be foliage all the way to the tips. If the ends are bare, there may be some future, serious problems.

o Groundcovers should be in a full growth period. New growth should be apparent on liriope, English ivy, periwinkle and pachysandra. If new growth from this spring season is not visible, or if it is less than normal, then investigate the problem…environmental stress, poor drainage, low nutrient availability, pH problem, construction damage to the root zone area or possible chemical injury. Be sure to check for insects. Aphids, mites and scales are serious problems.

o Summer Bedding Plants: Finish planting summer color beds. Don't take any short-cuts in the soil preparation stage. In order to maximize top growth and flowering performance, there has to be good root establishment and growth. This will only occur in well tilled, organically amended beds.

o Include Horticulture with the 2006 vacation: As you are taking vacations and traveling this summer, be sure to take time to drop in on a new garden center, nursery, botanical garden or arboretum. It's always a good place to get ideas for upcoming programs, or seeing something to share with others.

o June Pruning Tips: The appearance of many shrubs can be improved with a general pruning at this time of year. With new growth averaging 6” 8” long, many evergreens are getting slightly out of bounds. Now is a good time to take hand pruners and shape them up. This shaping is difficult to do with electric or manual shears. Individual branches and stems need to be cut...back inside the plant. This will reduce the overall size of the plant and also reshape it. Shears basically cut on one plane, giving that flat outer shape. It will take a lot longer, but the immediate look and subsequent growth will be worth the trouble. Formal hedges, "bowling balls" and "boxes" can continue to be sheared.

If the shrubs have turned into small trees over the years, now would be an appropriate time to get the big saw out and take them back to 12” 15" stems. The other professional approach is to limb up from the ground and accentuate the “tree look.”


If all else fails....remove the entire plant and start over again. Before replanting, evaluate the space to determine what type of plant, if any, is needed. This is often the best solution to overgrown plants.

o Compost Use: With all the effort you've gone through since last fall, it should be time to utilize the fruits of your labor (and garbage you've been saving). A properly functioning compost bin should be about "done" by now. Refer to one of the many information resources on Backyard Composting from the Horticulture Department if you need more information.


Azalea Care

Azaleas require little, if any pruning. The best time to prune is after flowering and before bud initiation in mid summer. Now is a good time to shape, or even rejuvenate.

Inspect for the following disease problems: Botrytis Petal Blight, Die Back, Leaf Gall, Leaf Rust, Mildew, Petal Blight, Phomopsis Die back and Phytophthora Root Rot. Also, inspect for the following insect problems: Caterpillars, Lace bug, Leaf Miner, Mites, Scales, Stem borers, Weevils and Whitefly.

Most azaleas are easily propagated from cuttings taken after the new growth is 4” 6” in length. This is usually performed in early to mid summer.

Keep azalea beds mulched with 4 6 inches of compost or other organic matter. Don't use materials that crust over (sawdust). Weed control is necessary throughout the year. If you use contact herbicides, be certain to shield the foliage as you spray.