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In the July garden, it’s high time to plant another round of summer vegetables

Summer! Temperatures soar both on the coast and inland. In July, we reap the harvest of spring vegetable planting — but please stay out of the midday sun.

Protect yourself

• • Garden before 11 a.m., then start again after 4 p.m. Stay out of the midday heat and sun.  
  • A full, wide-brim hat — not a visor — helps protect your scalp and eyes from the sun. Add polarize lens sunglasses to cut the glare. Dark gray lenses don’t distort plant colors as much as other colored lenses.

• Wear high SPF sunscreen, clothing, forearm protectors and lightweight gloves.

Water wisely

While we don’t have water restrictions this year, drought tolerant plants don’t need much water and, in fact, suffer if watered too often. Less is more.

• • Replace overhead irrigation systems with inline drip irrigation, 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. 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.
  • Check driplines. Flush the system to remove debris (Don’t have a flush valve? Simple ball valves are very easy to add). Repair leaks. Adjust drip line positions and use “staples” to secure lines in place.
  • Most gardeners water too often and for too little time. In our climate, we need to water “deeply and infrequently” for all plants other than vegetables.  
  • Figure out how much water your plants need:
    • How long to water: Adjust each irrigation zone’s run time to saturate the soil that surrounds plant roots. If you don’t know how long that is, here’s the test: 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, the soil should be damp from the surface down 12 inches deep, 8 inches deep for perennials and vines,  6 inches for everything else. 
    • How often to water: Do the Canary test by following this link: www.bit.ly/44xM5Wv
  • Mulch, mulch, mulch. Use stone or decomposed granite (DG) 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 or very early in the morning when soil is coolest.
  • Take control of your irrigation controller. Once you know when, how long and how often 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.  This is the ideal time to solarize your lawn to kill grass and seeds in the upper six 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 more information, watch my “Bye Bye Grass” webinar at www.bit.ly/byegrasslawn.

• Don’t use weed cloth, weed fabric, landscape cloth, etc. under mulch.  Weed cloth does not prevent weeds. Instead, it prevents water penetration into the soil, turns soil rock hard, and kills the important beneficial microbes plants depend on to be healthy and vigorous.  Ultimately, weed cloth breaks down and makes a mess that you’ll need to remove and throw away — it can’t be recycled or composted.

Vegetable garden

• Plant another round of summer vegetables from seedlings now: basil, pepper, eggplant, squash and other summer edibles. Harvest through fall.
• Plant okra and corn now — both thrive in the heat.
• Head off powdery mildew on tomatoes, cucumbers, squash, pumpkin and melon leaves with a quick rinse of water early in the morning. The idea is to wash away mildew spores 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 tomatoes and other vegetable plants does not increase their production, nor does it “redirect” energy to making fruit. Leaves are the engines that make energy for flowering and fruiting. The more you prune away, the less energy — and less fruit — plants make.
• Pruning shears and fingers transmit viruses and fungi from one plant to the next. Disinfect your tools and wash your hands between plants.  
• Concerned about curled tomato leaves? In the heat, fast-growing tomato plants lose water faster than roots can replace it. In response, leaves lose their turgor and roll their edges to shade the surface from the intense sunlight.  It is a simple response to environmental conditions and not a sign of pests or diseases. Deep water the next morning and watch for curled leaves to relax.  
• 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 worm’s presence. Pick off the worms and place on a table or other open area for birds to find and eat them.  
• Want your child to become a gardener? Plant sunflowers, zinnias and marigolds. Watch the critters that come to visit.  
• Problems with tomato pollination? 
  • For many tomato varieties, pollination stops when daytime temperatures exceed 85 degrees and nights exceed 75 degrees. 
  • If temperatures are in the optimal range, you can bee-come the pollinator. Bumble bees and other large bees (but not honeybees!) pollinate tomato 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. 
• Watch out for blossom end rot, the soft brown spots at the bottom ends of tomatoes, peppers and squash. Despite popular myth, blossom end rot is not a calcium deficiency. Instead, it results from uneven watering. Solve the problem by keeping soil damp (not wet) at all times. Mulch vegetable beds and containers with straw (not hay) to help hold in the moisture.
• Grow winter squash plants next to a trellis, mesh or tomato cage that tendrils can climb. Check beneath leaves for developing fruits. Pick them when the stem connecting to the vine starts to brown and pull away, or harvest the fruits after the entire vine dies at the end of the season.
• Do your small squashes or cucumbers turn brown and fall off before they ripen? Most likely those fruits were not fully 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 trails of leaf miners that burrow through the leaves. 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 always be damp but not wet. Use your finger to monitor the moisture.
• Plant roots cook in black plastic nursery pots this time of year. Paint pots white, drape them in shade cloth 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! 

Fruit trees

• 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,  www.nchfp.uga.edu/resources/category/usda-guide. 
• Compost fallen fruits so they don’t attract fruit flies, giant green fruit beetles, rodents and other pests to your garden.  
• Shorten branches of deciduous fruit trees right after harvest. Keep the branches short enough for fruit to be within reach. When the trees are dormant in winter, 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 orchard paint. It’s like sunscreen for fruit trees. 
• As tempting as it is to plant shrubs and flowers under citrus and avocado trees, don’t. 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. To get rid of the bugs, you have to get rid of the ants.  Use a boric acid-based ant bait and a spreadable sticky barrier to keep ants out of trees.  Use a sharp spray of water to wash off aphids; dab isopropyl alcohol onto mealy bugs and scale. 

Ornamental plants

• Plan, don’t plant.  It’s too hot to plant most drought tolerant ornamental plants now. Plan for planting once the weather cools in late October. 
  • 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. Cordylines have beautiful striped blades in shades of red, pink, maroon, cream, bronze and green. Some varieties stay only three feet tall, others reach 15 feet or taller.  They are very drought tolerant and beautifully sculptural.  
• Hold back on pruning and fertilizing. Both stimulate new growth, but this is the time for slow growth so that plants adapt to drought tolerance.
• Use a sharp spray of water to clean plant leaves of dust, dirt, aphids, white flies and spider mites, whose presence is evident by tiny webs on leaves and stems. 
• Plant spring-blooming dry summer bulbs now, since they are dormant.  Look for California native blue dicks (Dipterostemon capitatus), purple Tritelia and Mariposa lilies (Calochortus sp.) From South Africa come the fabulous bugle flower (Watsonia), baboon flower (Babiana), forest lily (Veltheimia bracteosa), and others.  Plant now. They’ll emerge in early fall.   

Container plants and houseplants

• Avoid those irritating fungus gnats by watering less. Add a layer of small gravel over the surface so the gnats can’t reach the soil.  Put potted plants in a protected spot outside for a few weeks. The natural predators will eat the gnats.
• Keep outdoor 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, continue to fill the pot until some water starts to drain out the holes in the bottom.  Wait a few minutes, then repeat.
• 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 garden designer, journalist and the host of “A Growing Passion” on public television. She runs Nan Sterman’s Garden School at waterwisegardener.com.