If you have some hot spots in your garden, simply place shade cloth over your precious plants and this will help protect them during high temperatures. Shade cloth protects plants from the sun, pests and wind. Lighter fabrics are draped directly on crops while heavier fabrics are used along with a hook system.
Once the sun comes up and temperatures rise above freezing, take the cover off. If you leave the blanket on, you run the risk of potential plant damage through excessive heating. You also want to give the soil more opportunity to warm up again.
Starting in mid to late September, it is beneficial to watch the forecast and take note of forecasted low overnight temperatures. Once temperatures dip to the mid-30s °F, it will be necessary to take action by bringing plants indoors, covering plants, or utilizing cold frames and hoop tunnels.
Depends on the plants and your goals. Most plants will be stressed out at 100+ but some tolerate it better than others. If I'm trying to grow things like lettuces in the heat, I will cover those even in 80s. Plants with strong established root systems will usually be OK whereas new plants can be more vulnerable.
The general answer is around 90 degrees F, with some exceptions to the rule. This means that when temps rise above 90 and remain there for a lengthy spell: Leaves wilt. Water evaporates into the atmosphere more quickly in high heat, draining a plant's reserves.
Select shade cloth covers that help tone down the intense sun without cutting the plant off from its ability to photosynthesize. Typically, this means a shade cloth between 30% to 60%.
During extremely hot weather (daytime temperatures above 90F and nighttime temperatures above 70F), try to water daily or every other day. In a 10x10-foot garden, this would mean giving your plants 8 to 9 gallons of water each day.
The time needed to recover from stress is proportional to the severity of the damage. Plant heat stress recovery may take months for crops that have been ignored for too long during a heatwave; in extreme cases, it may be impossible to bring them back to life.
Use Shade Cloth to Protect Plants from Intense Sunlight
Shade cloth is usually stretched over the plants you want to protect from intense sunlight, but can be positioned to one side. The rest of the plant is left open to allow air circulation.
Drought-stressed plants are susceptible to cold damage, so watering plants a few days in advance of a cold snap protects the roots.
So when temperatures start dipping below 50º F, leave the tomatoes on the vine if warmer days and nights are forecast. But if temperatures have started on a steady downward slide, go ahead and pick the mature green tomatoes and bring them indoors.
If using a good covering and the temperatures are expected to remain low, you can keep your plants covered for days.
Foliage will grow back unless the plant is too far gone. Water deeply. Use drip or soaker hoses for more efficient water use; water is lost to evaporation when using an overhead sprinkler. Roots extend beyond the plant, so be sure to cover an area wider than just under the plant.
So even though the weather forecaster isn't predicting a freeze, once temperatures start to drop below 40°F you need to be aware. Once temperatures drop below 40°F, you may want to start covering your plants with a frost blanket depending on what you're growing, which we'll get into in just a bit.
Common signs of heat stress in plants include leaves with crispy, brown scorched edges, leaf drop, cessation of bloom, bolting, wilting, and rolled leaves. These are all common, natural ways that plants protect themselves from the heat.
Many plants will wilt in the heat even when the soil has adequate moisture. The wilting process is caused by plants losing moisture through their leaves.
As long as the plant did not get too dry, the burnt leaves will slowly fall off as the plant grows new ones; remove any foliage that is more than 50% damaged and lightly fertilize to help it recover.
Outdoor plants are a great addition to any home or patio area. Figuring out the perfect balance of water to help keep them healthy and looking great is a must. Misting your outdoor plants is a great way to ensure you get enough moisture without overwatering them and without underwatering them.
Morning watering is actually preferable to evening watering as the plant has time to dry before the sun goes down. At night, water tends to rest in the soil, around the roots, and on the foliage, which encourages rot, fungal growth, and insects.
This depends on the plant types, garden light conditions, and weather. Plants in shaded areas may last longer without water compared to those in full sun. Container and window box plants can dry out in a day, whereas many houseplants can manage with one watering per week or less.
Make some shade
You can also use old bedsheets, rigged-up cheesecloth or propped-up cardboard to give your plants a break from the scorching rays, especially in the afternoon when temps reach their peak. Make sure your shade covering allows air to circulate freely around the plants.
While most of our garden plants need at least 6 hours of full sun to be productive, too much sun, especially when combined with too much heat, can be too much for plants to bear. Problems arise especially when temperatures are over 85 to 90 degrees F.