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Hot Weather Care For PlantsMaster Gardener Scoop – July 29, 2015

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Hot Weather Care For Plants

By Majo Bates, Master Gardener

I must admit, with all of the rain we’ve experienced this spring and early summer, I have gotten pretty lazy with not having to water my plants!!! Now that summer is upon us and we are suddenly experiencing HOT weather, I’ve had to really struggle to remember to take care of our plants and water them. Our plants were extra beautiful this spring with the addition of all the rain. It has been like a tropical paradise!

So how do plants cope with heat once temperatures begin to soar? When the weather suddenly skyrockets with temperatures above 85 degrees and very warm nights, many plants will inevitably suffer from ill effects. However, with adequate care and watering correctly, the heat stress on most plants can be minimized. It has been well above 85 degrees here in Southern Illinois. Since we’ve had some more storms, one never knows from day to day what to expect.

Generally, heat stress of a plant will show itself by wilting which is a sure sign that water loss has taken place. If we ignore this sign, the condition will worsen as the plants will eventually dry up and turn a crunchy brown before dying. In some cases, yellowing of the leaves may occur. Heat stress of a plant can also be recognized by leaf drop, especially in trees and shrubs. They are trying to attempt to conserve water; they may quit blooming or vegetable crops may quit producing. (Tomatoes, squash, peppers, melons, cucumbers, pumpkins and beans, for example, will usually drop their blossoms in high temperatures.) Blossom end rot is also common during hot weather which is very common in squash, peppers and tomatoes.

Good soil preparation is a plus in helping plants survive hot weather. Working in some organic matter to your soil first is a real plus. Also make sure that you purchase healthy-looking plants. Plants that are stressed from the start cannot withstand the heat as well as they could have. Pay a little extra and buy good, healthy plants and buy from a reputable place.

In my opinion, mulching plants, flowers and vegetables can help conserve moisture and keep plants cooler even in pots and containers! Additional watering is a given especially with any new plants and potted plants. The use of shade covers may be helpful as well. Some of us forget we can provide some shade. Our potted plants will require daily watering, even twice a day in very high temperatures! Our precious potted plants should be given a thorough soaking until water can be seen coming out of the drainage holes. Placing water granules in pots also helps. The granules will slowly release some of this water back into the soil. Reminder: Moving potted plants to a shadier location during the heat of the day is very much recommended.

When watering, soaker hoses are wonderful for large areas, as I do not like to irrigate over the leaves unless it has cooled off. You can literally boil and scorch the leaves which will usually start the death cycle.

I also want to share a list of a few flowers that are pretty heat resistant:

• African Daisy (Arctotis) flowers mid-summer to frost

• Bittersweet (Hymenoxys ororata)(Tetraneuris) these will even grow in cracks in concrete

• Blanket Flower (Gaillardia pulchella) an annual and comes in single and double-flowered varieties

• Butter Daisy (Melampodium paludosum) very easy to grow

• Cockscomb (Celosia cristata) do not purchase if root bound—check them out

• Dusty Miller (Senesio cineraria) an attractive foliage plant that works well in the garden for bringing plants together

• Fanflower (Scaevola aemula) blooms its head off

• Gazania (Gazania rigens) flowers close at night

• Lantana “New Gold” beautiful

• Mexican Sunflower (Tithonia rotundifolia) can be used as a temporary screen

• Moss Verbena (Verbena tenuisecta) makes a good nectar plant for butterflies and bees

• Plox “Intensia” attracts butterflies

• Rose Moss (Portulaca grandiflora) low growing and beautiful

• Sunflower (Helianthur annuus)

• Vinca (Catharanthus roseus) comes in both upright and prostrate forms

• Zinnia elegans, attracts birds, insects, butterflies and hummingbirds

Planting these flowers (and there are others) will help your garden blooms last throughout the hot summer weeks. They are tough and easy to grow. These plants do well in warm to mild summers also, so plant them and enjoy.

Time to get some ice tea and go sit out on the deck and enjoy God’s magnificent garden in my own yard! Enjoy yours as well.

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