By Courtney Brown, Conservation Garden Park
Life can sometimes be difficult in our arid, high-desert urban environment along the Wasatch Front, especially if you’re a plant. We live in a climate of extremes – extreme winter cold, periods of flooding, periods of drought, and this time of year, extreme summer heat. Many native and non-native plants do remarkably well living in the extremes, but when the rain is absent and the daytime temperatures stay in the triple digits or high nineties, our plants will struggle. Fortunately, there are some things we can do to help our plants survive the extreme heat of mid-summer.
It may seem obvious, but plants use more water when it’s hot. This is exactly the reason we need to understand the most efficient way to provide the water they need. Watering deeply but infrequently provides enough, but also encourages the roots to grow deeper in search of more water. Deeper roots make the plants more drought tolerant. It’s also best to use drip irrigation rather than spray in planter beds to minimize runoff and evaporation. Spray irrigation is fine for lawns, but should be applied at night or early in the morning to reduce evaporation. As a general rule, lawn areas only need water every two or three days during the heat of the summer, if they are watered deeply. Perennials, shrubs, and trees should only need water every five to seven days when they are watered deeply.
A thick layer of mulch does an amazing job of helping plants survive the extreme summer heat. Cover the bare soil with three to four inches of bark mulch, wood chips, crushed rock, or cobble rock. It really doesn’t matter what you use for mulch, so long as it is maintained at the proper thickness. In addition to looking nice, mulch helps keep moisture in the soil, adds nutrients, shades the soil, and discourages weeds. Weed fabric is not necessary. Inorganic mulch products like rock will last longer, but also retain heat longer. On the other hand, organic mulch products like wood will need to be refreshed more often, but may be cooler and help retain moisture better.
Pruning in summer is never a good idea. The last thing plants need when they are struggling in the heat is to receive any additional stress. Save pruning for late winter or early spring when plants are dormant. You can help lawn endure the heat by raising the lawn mower to its highest setting and mowing less frequently. This preserves more of the leaf blade and keeps the lawn healthier.
Right Plant, Right Place
If you have the opportunity to be proactive, do a little research when purchasing your plants. This will greatly increase their chance of making it through the extremes. Keep in mind that the growth and nutrient requirement of plants decreases naturally during summer, so a little love will go a long way.