Food & Garden: Keep your plants healthy in the summertime heat

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By Andrew Padula, Contributing Columnist and owner of Greer-based Padula's Plants:

Now that we are entering what is usually one of the hottest part of summertime here in the Upstate, there are many things to consider when it comes to the health of your garden and container plants.
As a general rule, most plants become stressed when the temperature around them climbs to 85 degrees or higher. This stress is usually increased by being planted in areas that have incorrect lighting requirements for the plant or from lack of water, or both.
Some things that you can do to help reduce this temperature induced stress is to make sure the plants have a fresh layer of mulch. This will help keep the roots of your plants cool. Since the roots are like the backbone of the plant, if they are unhappy then the rest of the plant is also. Most plants like their root system at a temperature between 65 and 75 degrees in the summertime. So a layer of mulch of 1 -3 inches in your garden and container plants will make a big difference in soil temperature. Along with mulch in your container plants, keeping the container out of direct sun will help keep the roots cool. In the summer sun, on a 90-degree day a plant container can reach 100 degrees or higher depending on its color and size.
When it comes to water, it seems the plants never get enough this time of year. You can help your plants retain water and at the same time decrease the time you spend watering them by adding a mixture of peat moss, broken up leaves, and red clay to the soil surface before applying your mulch. About an inch of this mixture under the mulch is enough to help the mulch in retaining moisture in the soil. This soil mixture also helps with adding organic nutrients to the soil.
The times of day that you water your plants is also important. Here at the plant nursery during dry weather, the plants get watered about an hour or so before sunset. This will help ensure that the water does not evaporate in the summer heat and sun, giving the plant all night to absorb the water it needs for the next day. This also gives the plant some time to dry off before darkness sets in. If because of your schedule watering the plants in the evening cannot happen, then watering them well between 5 a.m. and 7 a.m. is another option.
When the temperature is 85 degrees or higher, watering your plants between 11 a.m. and 3 p.m. can be counterproductive. This can cause the water droplets to act like magnifying glasses aimed at your plants in the mid day sun, burning the leaves. Also, at this time of day most of the water evaporates before the soil can absorb it. Most types of garden soil will take about an hour to fully absorb water.
It is also a very good idea to water your garden and container plants deeply this time of year. Rather then watering your plants every day for 15 minutes, water them 3 times a week for 30 minutes to an hour each time.
These high summer temperatures cause more than just the visual stress that you see your plant in. They wear down your plants' energy it would otherwise use to protect itself from pests and diseases. A stressed plant in the sun is much more likely to be attacked by insects that would like to have it for lunch than a plant that is well-watered with cool roots. Help your plants out by spraying them well about three times a week even if you do not see any plant pests. Many times the pest problem is not visible until it is quite large, so spraying the plants well is one way to help keep the pests from reaching that point. Spraying your plants also gives you peace of mind by helping to keep your garden chemical -free from insecticides. 
Lastly, any trimming that you do in the garden this time of year should be done on a cloudy day with temperatures not over 85 degrees or in the cool temperatures of the early morning. This minimizes the amount of water that the plant will lose from being freshly trimmed, while at the same time getting you out to enjoy your garden in much more comfortable temperatures during this hot part of the growing season.

Learn more about Andrew Padula and Padula's Plants here.

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