Gardening: Think light this summer for plants

Nancy Szerlag
Special to The Detroit News

Gardening in hot weather can be a real challenge because smaller pots, hanging baskets and window boxes sitting in the sun all day dry out quickly.

Plants planted in black nursery containers and pots suffer more than their counters parts planted in light colored pots or in the ground because the color black absorbs heat, so the daytime soil temperatures in black pots can be as much as 20 degrees more or hotter than the ambient temperatures.

Sinking the black containers in the ground or wrapping them in burlap will help keep the pots from heating up.

Painting the pots a light color, such as silver or white, is another solution. You can now buy paint for use on plastics in spray cans for under $5, which makes this project cheap and easy. Tent the plants and cover the soil with newspaper or plastic before you begin and do this project in the shade.

Newly planted trees and shrubs, especially those that were balled and burlaped, dry out much quicker than established landscape plants so they need special attention when the temperatures soar. Daily watering may be required for fresh plantings.

I use a Luster Leaf Moisture Meter, often found where houseplants are sold, to check the moisture content of the soil around plants I’m concerned about. You can also use it to check the moisture content in the lawn and garden. The simplest model is priced at less than $10. Experienced gardeners use their pointer finger. The rule of thumb for houseplants is when the soil is dry down to the first knuckle – it’s time to water.

In warm weather, most lawns need an inch and half of water or more a week to remain green. However, few homeowners know how much water they are putting on the lawn. A good way to check is to place several tuna cans on the lawn around the sprinkler head or hose end sprinkler. Run the water for 20 minutes and measure the depth of the water level in the cans.

The turf gurus at Michigan State University recommend making several light applications rather than one or two deep waterings to avoid over saturation and runoff.

Timely tip: If your container petunias are looking a little bedraggled about now, pinch them back by a third to encourage fresh new growth and flowering. However, wait until the temperatures drop to the low 80s to fertilize and do it in the cool of the evening or early morning when the plants are not in stress.

Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. E-mail her at , ask Nancy. You can also read her previous columns at detroitnewscom/homestyle.