Lance Ellis

Lance Ellis

We all know hot weather can be tough on plants if they do not have adequate water, or if the hot weather is made worse with drying winds. Most plants slow down their growth and production in temperatures above 90 degrees. Tomatoes for example, which are a warm-season crop, basically stop growing and producing leaves, stems and tomatoes above 90 to 95 degrees. Cooler-season plants such as peas will not only stop growing, but can also deteriorate and die in hotter temperatures.

The best way to manage the effects of hot temperatures on plants is adequate and consistent watering. Inconsistent watering and hot temperatures lead plants to shut down for the season. Their natural biological response to die or deteriorate are triggered by these two environmental conditions and make the plant focus on seed production so there is genetic material for the next generation the following year. A vegetable stressed by the environment and trying to produce seed will result in low-quality produce. By comparison, a vegetable that has proper watering during hot periods will continue to deliver good-quality produce, though it may be slowed down due to plant processes also slowing down in response to heat.

One crop that doesn’t seem to grow a whole lot without the higher temperatures and may seem stagnant until hot weather arrives is peppers. It can almost appear that peppers double in size and growth when temperatures get above 80 degrees as they are a heat-loving plant.

During the summer growing season, watching for diseases in your plants is critical. It is astounding how quickly a bad disease or fungus can infect a plant and then spread throughout the garden. I have seen a disease on a tomato plant start one day by infecting a small branch, and then within three days spread to the entire plant and kill it off. A good rule of thumb when it comes to finding a disease in you garden is to immediately remove the infected plant or plants and put them in a plastic bag and dispose of them. Do not compost the infected plant, it only increases the risk of infecting more plants in the future. And for most homeowners, buying a chemical to apply to control an existing disease is not cost effective when you consider the cost of the chemical compared with the amount of food that would have been produced. Most diseases when noticed have already moved throughout the entire plant and there is no saving it. Removal and quarantine of the problem is the best method. Be careful when removing diseased plants so that you don’t spread the disease to other plants, and handle them gently without distributing spores or disease organisms to surrounding plants.

Lastly, I am often asked at this time of year how to make weeding your garden a less miserable experience. Weeding should be done in the morning, early, before the sun is up and getting hot, such as 6 a.m. to 7 a.m. But, most people do not want to get up that early in the morning and weed a garden, so another option is planting a shade tree that provides, “filtered shade” next to the garden. A filtered shade tree is one that provides some sunlight through the tree canopy, while still giving you ample shade to make the experience enjoyable, and not roasting you to death. The two drawbacks to planting a tree alongside the garden or even in the middle of it are reduced sunlight for your vegetables, and competition for water and nutrients that a tree may pose to garden plants. Planting vegetables that are somewhat shade tolerant such as lettuce and spinach.

in filtered shade can work, but sun-loving crops such as peppers and tomatoes will struggle under shade conditions. Watering more will provide enough moisture for both the tree and the veggies, and adding composted manure or chemical fertilizers annually can compensate for the increased nutrient needs of both the tree and garden plants. Tree roots can also become a problem if the tree is shallow rooted, as they can be damaged when tilling the soil. Shade when weeding comes at a price, and sometime the best remedy is a wide-brimmed hat and an alarm clock to get you up early in the morning. Enjoy your gardening.

Lance Ellis is the University of Idaho Extension educator for Fremont County. He can be reached at 208-624-3102.