Hot Weather Gardening

In July and August when the temperatures rise so high you think you may melt, plants needs change just a bit. Here are a few tips on how you can help your garden thrive during the heat waves of mid-summer.

Some hot weather gardening DO’s and DON’Ts


During July/August in Ohio, temperatures often reach very high numbers. This can mean stress to your plants and even the end to your garden if not addressed properly. Since high temperatures are often in conjunction with little to no rain, you may think your plants need extra watering, but knowing when and how to water during high temperatures is essential to keeping your garden healthy and producing for you.

• Water very early in the morning. If the temperatures are in the 90’s with heat index into the triple digits, the soil will also be very hot. Watering during the heat of the day (afternoons), can cause the water temperature to rise so high it will either evaporate too quickly to do any good, or it can become so hot that if it reaches the roots, can begin to cook them. Try to water very early in the mornings or late evenings after the sun has started to go down. This will give the water a chance to reach the roots without being too hot and try to avoid getting leaves wet. If you must get leaves wet, if watering in the mornings, do so early enough that the water will evaporate off of leaves before the sun gets hot enough to burn them. If watering at night, leaving leaves wet throughout the night can encourage mold.

• Avoid over watering. During the heat of summer, we drink extra water to keep our bodies cool. Plants may not necessarily need “extra water” during this time, however. Typically, Ohio in July/August, has little rain, but humidity is also high and the leaves of plants will absorb that moisture. Your plants will tell you if they need water. They will become stressed and wilted, leaves will begin to curl and stems begin to droop. This is a time when you may need to break the rule and water in the afternoon, but be sure to keep water off of leaves to avoid burns. If your plants are just beginning to stress in the heat of the afternoon, it’s best to wait until evening when the sun isn’t as intense to water if at all possible.


Plants are naturally designed to grow through the summer. Their internal systems will trigger them to stop new growth during the high temperatures, as growth takes up a lot of energy and they need to conserve energy to survive the heat. When they are fertilized, the roots send signals to the plant to grow. When adding a fertilizer during their growing break, this can use up too much energy and cause the plant to die off. So, with this in mind, avoid fertilizing on those days when the temperatures reach 90 f or above. Leave it for when the temperatures drop back into the 80’s.

There is a lot of debate on what time of day is best to harvest. It is a personal preference, on what time of day you want to pick your tomatoes, but one thing that is a must, is that you pick ripe fruits and not leave them on the plant. Especially during a heat wave. Plants continue to support the fruit they bear as long as it is on the plant. This means the plant is sending nutrients and using energy to sustain the fruit and this can cause extra stress on plants at a critical time of the season. By harvesting the fruits, you are allowing the plant itself to retain as much energy as possible, and therefore creating a healthier plant that can produce more when the temperatures lighten up.


Often times, we see gardeners who simply get tired or busy in the middle of the growing season, which is when we have the most heat and least rain, and end up getting behind on their weeding. This can cause extra stress to plants due to the fact that the weeds are competing for nutrients and can deplete plants of what they need during this stressful time. They cause soil to dry out more quickly as well and make it hard to get to your plants for harvesting and watering.

Pest Control

As things heat up in the garden, the bugs come out to play. This can be irritating to you and your plants. Seeing your beautiful plants looking like swiss cheese can cause alarm, but spraying pesticides during heat waves will only harm your plants. The sun will burn leaves and cause more damage than the bugs do. It’s best to wait until the temperatures drop a little.

We all agree, gardening in 90 F temperatures is not fun, but keeping diligent by working mornings or evenings, will help the overall health of your garden, and your plants will thank you for it.

Until next time, Happy Planting!

“To plant a garden is to believe in tomorrow” ~Audrey Hepburn