Moisture is lost from hot air, particularly hot, dry wind. Some evaporation from leaves is normal, but when vital moisture is being evaporated faster than the plant’s ability to replace it, leaves dry out and wilt. First symptoms of hot air injury are drying and browning at the tips and edges of older leaves. Rapid moisture loss can cause tender leaves to turn black. Evaporation cools foliage, but if it doesn’t get water from the roots fast enough to provide the evaporative cooling effect, the foliage gets hot, tender growth wilts and older leaves sunburn.
Stunted plant growth and yellow-white burn on the upper surface of older leaves are familiar symptoms of too much intense sunlight.
You are thinking of watering the plants. How long and how often to water depends upon how long the soil retains moisture and how fast that moisture is being used. A proper balance of moisture and air in the soil is necessary for roots for roots to breathe and do their job. If you want to fertilize during hot weather, use caution. Increasing living processes of plants during hot weather use up nutrient reserves faster. However remember, increase the fertilization frequency, but decrease the amount applied each time. Fall fertilization helps plants recover from summer exhaustion. Spring fertilization encourages strong growth to better withstand summer stress. Using organic mulches spread over the soil surfaces under plants provide a practical insulation against summer heat. Mulching shades the soil and keeps it cooler. It also reduces soil moisture evaporation. When you are using mulches remember mulch retains soil moisture longer.
Remember, how long and how hot the summer will be, there is a right way and a wrong way to insure that your plants thrive and survive.
Stay cool and keep your plants cool. See you at market.