We've been having typical July weather lately with high temperatures and high humidity. Drought and heat are inevitable challenges for your fruit and vegetable plants. Most plants require around 2 – 3 cm of rainfall per week for normal growth. This need increases when temperatures rise above 32 degrees. Don't wait until your plants show stress. If they wither, damage and loss of yield have already occurred. Some plant damage caused by heat and drought (see pictures below) are described below: These are the typical problems that you have in the kitchen garden in summer!
Avoid plant damage in hot and dry conditions
Water vegetables and fruits properly
Avoid the onset of drought stress by watering your plants before the soil becomes extremely dry. Depending on the type and condition of the soil, dry soil can sometimes be very difficult to moisten again.
Use drip irrigation, where the water goes directly into the soil rather than into the air or onto the leaves. Drip irrigation is 90-95 percent more efficient than irrigation with sprinklers. Additionally, the water is distributed more slowly, allowing more water to penetrate the soil and wet a deeper soil profile.
Make sure you water deeply. Superficial watering can be more harmful than no watering at all. When watering, ensure that the moisture reaches a soil depth of at least 15 - 20 cm. Otherwise, plant roots will be concentrated near the soil surface, making them more vulnerable to drought and heat.A deep wateringpromotes deeper rooting and more resilient plants. Check your system by regularly digging into the soil profile after a watering cycle to determine how deeply the soil is wetted. If the water does not reach the recommended depth, you will need to increase the watering time or the number of watering cycles, or both, depending on the soil type and irrigation system.
Use organic mulch in the kitchen garden
Use organic mulch (shredded leaves, straw, hardwood mulch, etc.) to reduce water evaporation from the soil and insulate the soil and plant roots from extreme heat.
Avoid plant damage in hot and dry conditions with shading
Consider temporary shading to protect plants during periods of extreme heat.
Most vegetables prefer full sun to thrive, so shade should only be used temporarily during the hottest weather.
Tomato damage
White spots on tomatoes are sunburn. They kickat high temperatureson fruits or plants (and trees) that are not adequately protected from direct sunlight. If there is sun damage, it does not mean the plant is doomed. Sunburn on tomato fruit does not result in the death of the tomato plant. This is usually a temporary problem.
Remove damaged fruits to reduce stress on plants. If the tips and ends of the branches have been damaged, cut them off too. Many good gardeners report cutting back the entire top portion of the plants that were most affected.
It is a good idea to give the plants extra water during these hot times. Extensive waterings are better than a little water per day. However, container plants most likely need water daily. You should also feed the tomato plants to reduce the shock of sunlight. You can use a nitrogen-containing, organic liquid fertilizer to stimulate new leaf growth.
Tip: Save some tomatoes
You can bring tomatoes with small spots indoors and let them ripen on the vine. Wrap them in newspaper and place them on the counter. If you cut off the damaged parts, they are still usable. Check them every few days to make sure they aren't rotting.
Heat Stress Symptoms in Cucumbers
Cucumbers sometimes wilt in high heat, especially if the heat is accompanied by dry wind. Under these conditions, the leaves lose water faster than the roots can absorb moisture from the soil. Plants can recover from one or two heat spells, but continued wilting can result in reduced yields orpoor fruit quality, stunted growth and even death of the plant.
To prevent wilting from heat stress, water more frequently. This is a time when the use of overhead irrigation is appropriate and even desirable. Mulch the soil with straw or untreated grass clippings to retain moisture, and stretch a fabric shade cloth over the plants.
Damage to plants in heat and drought: zucchini
In some situations, the sun can burn the developing zucchini: this usually happens with plants affected by downy mildew. Leaf loss from this fungal infection causes the previously protected fruit to suddenly be exposed to the sun, increasing the risk of pale, spongy spots on the zucchini's surface.Downy mildewusually occurs in warm, humid conditions and can develop within a few days. Keeping plants dry at night can help prevent infection.
Damage to apples
Sunburn is not a disease, but damage to apples and many other fruits caused by high temperatures and strong sunlight in summer.
Typically, sunburn damage occurs on the sun-exposed side, which is usually toward the midday to afternoon sun. The cellsin the sunburnt areadie and form an irregularly shaped reddish-brown spot that has sunk below the surface of the fruit. The flesh under the damaged area also turns brown. Fruits with sunburn damage tend to fall prematurely.
Sun damage to berries
Strawberries, raspberries and blackberries can also be affected by sun damage.
