Stillwater News Press

August 14, 2010

In the Garden 8-15-10

By LeeAnn Barton
Stillwater NewsPress

— Plants and I have a lot in common. We both like to stretch our toes in loose soil; we both enjoy a sunny day. Nutritious food strengthens us, and we are always thankful for a good, long soak.

It is entirely probable (because God answers prayer) that by the time you read this column the issue of soaking your garden beds is a moot point. Nevertheless, I receive phone calls and e-mails from customers regarding plant and tree death whenever we enter into a prolonged period of extreme heat.

Many times, in spite of regular watering, a plant will up and die; however, how one waters can affect the health and survival of plants during a heat wave.

First let’s address the time of day one waters. My niece admonished me, “Dad says if you water at night it brings mosquitoes.” Wrong. In spring and fall, watering in the morning is recommended because nighttime temperatures hover in the 60s and 70s — the ideal temperature for many fungal, mold and mildew issues to arise and proliferate. The same strains are not active when our lows are in the 80s.

It is common knowledge that a plant will wilt in the heat of the day to protect its leaves from the sun’s intense rays. The stomata (pores) on the underside of the leaf close themselves to conserve moisture. As evening cools, the foliage will then lift back up, pores open and transpiration (breathing) resumes.

Picture a plant, watered in the morning, taking in gulps as the sun is on the rise. Within hours the plants’ functions shut down and the water in the stems and leaves reaches 105 degrees. Water holds heat in the soil and in the plant. The stress of a plant in this scenario day after day is extremely high. Root rot, especially in containers, is predictable.

 I prefer watering in the evening with a good long soak. The water helps cool the soil and allows the plant to drink its fill and rest. Soaker hoses should be allowed to run at least two hours. It may not seem like much, but you will find your beds can look good with bi-weekly rather than daily watering.

Sprinklers help cool the air around the plant, but do not replace a good soak. Overhead water only where foliar diseases (like black spot) are not present. Sprinkling an area once the sun’s rays have departed gives the birds, dragonflies and butterflies a chance to cool off, too.

LeeAnn Barton can be e-mailed at