August is the time of year gardeners want to kick back and enjoy the view. But it’s also a time to do some troubleshooting to look for the good, the bad and the ugly. Some problems are best taken care of now, some can wait until fall and others might be handled in spring. My tools of choice for this job are a camera, smartphone or tablet and a pad of paper or 2017/18 calendars.
Trees are the No. 1 plant on my list, but I keep an eye on them all year. Bouts of drought and rapid changes in temperatures have taken their toll on our urban forests. Trees under stress are vulnerable to diseases and insects.
Loss or thinning of leaves in a portion or the entire canopy is a good indication of a problem. Yellowing of leaves or needles before fall is another. Discolored needles on evergreens and spots or splotches on the leaves of deciduous trees are indications of trouble — and it will only get worse.
Insect damage is a whole other issue. When folks ask me how to treat these problems, I refer them to a professional, a certified arborist who has the knowledge, the proper equipment and chemicals to properly diagnose and treat problems. To find a certified professional in your area, go to tcia.org and enter your ZIP code.
Hydrangeas that fail to bloom or even thrive may need transplanting. It’s best to do that when the shrubs are dormant in late fall or very early spring, before bud break. A location that protects hydrangeas from the hot afternoon sun is best, and avoid locating them under trees where they will fight a losing battle for moisture.
Shrubs and trees that sport leaves with slight yellowing between the veins are usually suffering from lack of iron. This often happens to hydrangeas and red maples. However, now is not the time to fertilize trees and shrubs, as it promotes new growth that may not harden off by winter and will be subject to winter kill. But garden centers carry iron-based products in liquid form that plants can utilize safely at this time of year.
Taking pictures and listing annuals and perennials that thrived in the garden as well as those that failed to meet your expectations will help you make better choices next spring. These photos also help when making decisions as where to site new plantings in spring.
Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to Yardener.com and click on Ask Nancy. You can also read her previous columns at detroitnews.com/homestyle.