THE COASTAL GARDENER:

Summer is here, and our gardens are now being treated to occasional periods of very hot and very sunny weather. Just a few days ago, temperatures were in the 60s at night, shot up to 80 degrees by 9 a.m., and just a couple of miles inland were near 100 degrees by noon.

We’re certainly in for more periodic heat spells during the next two or three months, so prepare now. Hot summer temperatures can be the bane of many local gardeners’ existence.

Here are a few tips:

 Strong plants withstand heat better than weak plants. Make sure thirsty plants are well-watered and well-tended before extreme temperatures hit. Some plants, like tomatoes, squash, fuchsias and hydrangea, will wilt during the hottest part of the day, no matter how well-watered they are. The plant is simply losing water through a process called transpiration, faster than its roots can replace it. If it recovers in the evening, it’s nothing to worry about. A cool spritz of water on the leaves or in the area around the plant will slow down transpiration and also perk the leaves back up.

 If watering by hand, remember to let the garden hose run for a minute or two, until cool water comes out. Never hose down plants with hot water!

 Learn about the plants in your garden and research their water needs as well as the times of the year when they need the most water and the least water. If you’ve planned well, plants with the same water needs will be grouped in the same irrigation zone. This is called hydrozoning.

 Morning is the best time to water plants, although a quick, cooling rinse in the afternoon can be quite helpful and uses very little water. Newly planted transplants may even need watering twice on extremely hot days.

 Check the soil. It may be dry on top but moist four or five inches below, where the roots are. If the soil still has moisture at this level, wait another day and check again. Don’t necessarily water just because the surface of the soil is dry.

 Potted plants are especially at risk during the hottest days, mainly because pots provide little insulation and heat up faster than the ground, thereby drying out the soil quickly. Black pots absorb heat more than lighter colors; a benefit in winter, but a detriment in summer. Group several pots together so they can shade and humidify each other. If using a hose, irrigate until water comes out the bottom.

 Mulch, mulch, mulch. It keeps the ground from heating up and drying out, and it conserves water.

Mulch is a must for summer gardens. All plants benefit from a two- to three-inch layer of organic matter to insulate the soil.

 Tomatoes, peppers, melons, squash, pumpkins, cucumbers and beans often drop their blossoms without setting fruit when day temperatures get into the high 80s or the 90s.

There’s not much you can do but wait for cooler temperatures to prevail. As more favorable conditions return, the plants will resume their normal fruit set.

 Many established California native plants can survive with little or no summer irrigation. They may enter a stage of “evergreen dormancy” while they hang on through the hot, dry months. More water won’t help and may actually harm them. Use restraint.

 Look at your plants every few days and see how they are doing. Check for and repair any problems with clogged drip emitters, sprinklers that don’t pop up or irrigation timers that aren’t working.

 Remember, let the garden hose run in a bucket or watering can until cool water comes out. Never hose down plants with hot water!

 Avoid pruning most plants during the summer. Removing too much leafy growth will expose the stems and branches to strong sunlight that can cause the wood to sun-scald, a common problem on plants like avocado, citrus and plumeria.

 Put a piece of shade cloth or an umbrella over young plants or plants at risk of sunburn.

Sultry summer weather is not only tough on your plants, but on gardeners as well. Try not to over-exert yourself on extremely hot days. Aim to complete your chores early in the morning or in the evening when the sun is less intense. Take frequent breaks, and drink plenty of water to keep yourself from wilting as well.

ASK RON

Question: My apricot tree is loaded with fruit. They’re small fruit, but delicious. They’re everywhere, on the tree, falling on the ground; I can’t eat them all. What do I do?

Enna

Answer: Bring them to me, of course! Many stone fruits over-set their fruit, and since they ripen during a very short window, it is often too much to handle. Apricots can be frozen; usually pitted first. Soaking them for a few minutes in ascorbic acid (vitamin C) will prevent discoloration. I also suggest thinning the fruit on the tree when it is about the size of your fingernail, usually in April. This will produce less fruit, but considerably larger fruit.

ASK RON your toughest gardening questions, and the expert nursery staff at Roger’s Gardens will come up with an answer. Please include your name, phone number and city, and limit queries to 30 words or fewer. E-mail stumpthegardener@rogersgardens.com, or write to Plant Talk at Roger’s Gardens, 2301 San Joaquin Hills Road, Corona del Mar, CA 92625.

RON VANDERHOFF is the nursery manager at Roger’s Gardens in Corona del Mar.