Beat the heat in your July garden: How to keep your plants — and yourself — from drooping - The San Diego Union-Tribune

2022-07-22 22:49:17 By : Ms. Amy Li

Summer! The coast is clearing (literally) while inland, temperatures soar. July is the time to reap the harvest and stay out of the midday sun.

• Set your alarm for early morning gardening. Finish before 11 a.m., then start again after 4 p.m. Stay out of the midday heat and sun.

• Heads matter. Wear a hat that shades your face and covers your scalp.

• The sun is at its zenith, so focus on SPF. Sunscreen, clothing, even lightweight gloves are standard gear year-round, and especially over the next few months.

Water restrictions are here again. If your water agency hasn’t yet established water restrictions, expect them in the next few months. Since this is the time of year when outdoor water use peaks, give your garden a water tuneup.

• Inspect overhead irrigation systems. Fix leaks and broken heads, adjust spray that lands on sidewalks and streets.

• Check driplines. Flush the system (Don’t have a flush valve? They are very easy to install.) to remove any debris. Repair leaks. Adjust lines and use “staples” to secure in place.

• Switch to inline drip. Inline drip irrigation is the most efficient kind of irrigation and the only type to use if you mulch your garden (which you absolutely should do). Drip lines sit on top of the soil, beneath mulch, so water drips directly onto the soil. Spray over mulch uses MORE water, as the mulch has to saturate before water can reach plant roots in the soil.

• Most gardeners water too often and not nearly long enough. In our climate, our watering mantra is “deep and infrequent,” for all plants other than vegetables. Figure out how much water your plants need:

1. How long to water. Run each zone according to its normal schedule. Stick your finger into the soil, dig down with a trowel, or use a soil probe to see how deep the water has gone. For trees and shrubs, water needs to penetrate 12 inches deep, 8 inches for perennials and vines, 6 inches for everything else. Adjust each irrigation zone’s run time to saturate the soil surrounding plant roots.

2. How often to water. Do the Canary test, follow this link: tinyurl.com/canarytestgiveaway

• Mulch, mulch, mulch. Stone or decomposed granite mulch for succulents, wood-based mulch for all other ornamentals (NOT BARK), straw for vegetables (NOT HAY).

• Run spray irrigation early in the morning, so leaves dry before nightfall. Run inline drip at night, when soil is coolest.

• Take control of your irrigation controller. Once you know how long, how often and when to water, use that information to set your controller. Lock the cover so you are the only one who can adjust it.

• Lose your lawn now! This is the ideal time to solarize your lawn to kill the grass and all the seeds in the upper 6 inches. Cut the grass short, water to saturate the soil, then cover with CLEAR (not black) plastic. Use the sun’s rays to superheat the soil, using the greenhouse effect. For detailed directions, go to tinyurl.com/killerrays.

• Don’t use weed cloth, weed fabric, landscape cloth, etc. under mulch. Weed cloth does not reduce weeds. Instead, it turns soil rock-hard and kills the important, beneficial microbes that plants depend on to be healthy and vigorous. Ultimately, weed cloth breaks down and makes a mess you’ll have to remove.

• Plant another round of summer vegetables from seedlings now: tomato, pepper, eggplant, melons and other summer edibles. Harvest in fall.

• Plant okra now. They thrive in the heat.

• Head off powdery mildew on tomatoes, cucumbers, squash, pumpkin and melon leaves by giving them a quick rinse early in the morning. The idea is to wash away mildew spores that have settled on leaves, in time for leaves to dry before the cool of night.

• Selectively remove branches (not individual leaves) of plants with powdery mildew to improve air circulation.

• Pruning vegetable plants does not increase their production. Leaves make the energy that supports flowering and fruiting. The more you prune away, the less energy — and less fruit — plants can make.

• Pruning shears transmit viruses and fungi from one plant to the next. Use your fingers instead and wash your hands between plants.

• Concerned about curled tomato leaves? In the heat, fast-growing tomato plants often lose water faster than roots can replace it. In response, plants roll the edges of leaves to shade them from the intense sunlight. It is simply a response to environmental conditions and not a sign of pests or diseases. Usually, curled leaves relax by the next morning.

• Check for white, green and yellow striped tomato hornworms. These moth larvae can strip a tomato plant of leaves almost overnight. Check the area for tiny black balls (that’s worm poop) that are evidence of the worms’ presence. Pick off the worms and place on a table or other open area for birds to find and eat them.

• Want to involve your child in the garden? Offer to pay them a quarter for every tomato hornworm they collect.

• Problems with tomato pollination? Imitate buzz pollinators. Tomato flowers are pollinated by bumble bees and other large bees as they visit the flowers. Their beating wings vibrate, inadvertently loosening pollen, which then falls onto the female part of the flower. You can mimic the process by holding the backside of an electric toothbrush very close to the backside of a tomato flower. By the way, honeybees do not pollinate tomato flowers.

• For some tomato varieties, pollination stops when daytime temperatures are hotter than 85 degrees and nights are hotter than 75 degrees. Buzz pollination doesn’t work at these temperatures either.

• Watch out for blossom end rot, the soft brown spots at the bottom ends of tomatoes, peppers and squash. Blossom end rot results from uneven watering. Solve the problem by keeping soil moist at all times. Mulch vegetable beds and containers with straw (NOT HAY) to help hold in the moisture.

• Grow cucumber plants next to a trellis, mesh or tomato cage that tendrils can climb. Check beneath leaves for developing cucumbers. Pick them on the small side when the seeds are soft and the flesh tastes sweet.

• Do you find small squashes or cucumbers that turn brown and fall off before they ripen? People often think the fruits have blossom end rot, but actually, they abort because they were not properly pollinated.

• To fertilize or not to fertilize? If you prepped the soil with vegetable fertilizer and added some to the planting hole, you may not need to fertilize again. If you see evidence of nutrient deficiencies — leaf discoloration, stunted plants, etc. — then fertilize.

• Do you see curly patterns in leaves of squash and related plants? Those are leaf miners, which burrow through the leaves. Don’t worry about them. They don’t diminish production much. And since they are literally inside the leaves, no pesticides can reach them.

• Whiteflies? Spider mites? Hose off leaves, top and bottom, with a Bug Blaster garden hose attachment every few days for a week or so. By interrupting their reproductive cycle, they’ll disappear.

• Monitor moisture. This time of year, garden beds should be damp but not wet at all times. Use your finger to monitor the moisture.

• Hot pots — plant roots can cook in black plastic nursery pots this time of year. Paint the pots white, drape them in shade cloth, or drape them in burlap so they don’t heat up so much.

• Fabric plant pots dry out very, very quickly in our arid climate. Check the soil moisture every day; it should stay damp. Some people put their pots into a kiddie pool and add a few inches of water when pots start to dry out. The water wicks up to the top — very efficient!

• Harvest fruits as they ripen. Can the extras or freeze now to can in winter. Check the USDA Complete Guide to Home Canning on the National Center for Food Preservation website, nchfp.uga.edu.

• Compost fallen fruits so they don’t attract fruit flies, giant green fruit beetles, rodents and other pests to your garden.

• To keep deciduous fruit trees short so fruit is within reach, cut branches back after you pick all the ripe fruits. In winter, when the trees are dormant, prune again for structure and to promote next summer’s fruits.

• Fertilize and water citrus, avocado, mango, banana and other subtropical fruiting plants.

• Protect exposed trunks of citrus and avocado trees from sunburn by painting them with half water/half light-colored interior latex paint mixture, or use trunk paint designed for fruit trees.

• As tempting as it is to plant shrubs and flowers under citrus and avocado trees, don’t do it. Those plants compete with citrus for nutrients and water — which in the long run can reduce production.

• Check for ants! Ants carry scale, aphids and mealy bugs into fruit trees. Before you can get rid of the bugs, you have to get rid of the ants. Use a boric acid-based ant bait and a sticky barrier like Tanglefoot to keep ants out of trees. Use a sharp spray of water to wash off aphids, dab isopropyl alcohol onto mealy bugs and scale.

• Plan, don’t plant. It’s too hot to plant most drought-tolerant ornamental plants now. Plan for planting in October, once the weather cools.

In summer, most native plants sleep to conserve moisture and avoid the heat. That’s why chaparral-covered hillsides turn brown. That’s the normal cycle. In your garden, hold off watering natives — even when they look dead.

Focus on foliage when flowers are not plentiful. Bromeliads are the ultimate foliage plants. Their broad blades can be green, bronze, gray, blue, striped, spotted, banded and more. Many bromeliads are extremely drought-tolerant, too. Learn more here: agrowingpassion.com/episode-701-the-beautiful-bromeliad/.

• Hold back on pruning and fertilizing. Both stimulate new growth, but this is the time for slow growth. That helps plants develop their drought tolerance.

• Use a sharp spray of water to clean plant leaves of dust, dirt, aphids, whiteflies and spider mites, whose presence is evident by tiny webs on leaves and stems.

— Spring blooming native and South African bulbs are dormant now, so this is the time to plant them. Look for Calochortus, Ixia, Veltheimia, species Gladiolus, species Tulips (not the fancy, high chill tulips), Babiana and others. Plant now. They’ll emerge in early fall.

• Fungus gnats! So pesky! Discourage them by managing water — don’t overwater. Add a layer of small gravel over the soil surface. Put the pots in a protected spot outside for a few weeks. Their natural predators will eat them.

• Keep container plants watered — monitor the soil and water when it gets too dry.

• White crusts on soil or pots is accumulated salts from our high mineral water. Remove plants from their pots and wash soil off the roots. Scrub the crust off the pot, then replant into fresh potting mix (NOT planting mix, dirt, peat moss, etc.).

• When you water, fill the pot completely and watch for some water to drain out the holes in the bottom. Wait a few minutes, then repeat.

• Manage too-long pothos vines. When the vines get long and leggy, just cut them back to a leaf node and root the part you cut off in damp potting soil.

• Give your houseplants a summer vacation. Put them outside under the eaves, the branches of a shady tree, or in an east-facing spot with morning light. Use the hose to give them an all-over shower. Let the native predators pick off scale, mealy bugs, thrips, etc. Bring them back inside when the weather cools in fall.

Sterman is a waterwise garden designer and writer and the host of “A Growing Passion” on KPBS television. More information is at agrowingpassion.com and waterwisegardener.com.

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