Hot Season

Our fleeting summer feels like it has just begun, but here it is August already. Plants can now expect a full day of sunlight and maximum photosynthesis. Temperatures are also as warm as they are likely to get here, so growth rates are as rapid as our coastal climate can afford. Gardeners on the other side of the coastal range have had lovely sunny and warm (even hot!) temps for the last month and should be reaping the benefits, like luscious, ripe tomatoes, show-quality dahlias, or juicy peaches.

What to do to prolong the summery feel in the garden? There is still time to plant many heat-loving plants, but if you want to get in some beans or tomatoes, for instance, you’d better do it soon. There will be a couple of months of warm days, so pick varieties that will mature early enough or that don’t mind the chillier nights that will sneak in by mid October. In the vegetable garden, one last sowing of pole and bush beans, corn, and even tomatoes is possible.

Tropical and subtropical trees and shrubs will also still do well if planted now. Palms and cycads are among this group. They have time to put on new root growth before the soil cools down and they slow to a standstill. This is a great month to transplant these architectural accents, too. If you’ve just discovered a palm seedling growing behind the compost bin, don’t be afraid to dig it up and relocate to take advantage of its ability to instantly give any area an air of the tropics.

Many plants are still growing rapidly, so it is also a great time to do a little light pruning to shape them. These include citrus, bougainvillea, roses, and summer-flowering trees. Fruit trees may be making water sprouts this time of year, too. These strong vertical shoots (also called suckers, especially if they grow from the base of the tree) should be removed completely. Be sure not to leave stubs behind as they will just sprout again with more of this unproductive growth.

The humidity is definitely reduced this month, so woody plants—trees and large shrubs—may be particularly thirsty right now. Give them a deep soaking that covers the root zone (under the drip line of the canopy and beyond, even) and that wets the soil at least 18 inches down. Soaker hoses work great for this; sprinklers tend to deliver too much water at once, and it can’t percolate into the soil as fast as it is arriving. So if you only have sprinklers, turn them on repeatedly for several shorter waterings until the soil is saturated deeply enough.

Keep an eye out for insect pests like spider mites, aphids, and thrips. These sucking insects can really stress plants during the warm months. A blast from the hose is the best first response. This time of the year, there may also be an outbreak of a species of scale insect that attacks members of the genus Araucaria. The bunya bunya trees (A. bidwillii), in particular, may be showing some brown foliage—a dismaying sight. But an even more astounding sight is the appearance of the mealybug destroyer (Cryptolaemus montrouzieri) that also appears on schedule to feast on these insects and provide the perfect natural control for them. What is even more interesting is that the fuzzy-looking white insects that proliferate in response to the infestation look just like another sucking insect, the mealybug.

Lastly, be sure to go to the Santa Barbara County Horticultural Society’s annual plant sale. It will be held at McKenzie Park on Sunday, August 21.