San Diego Gardener
Southern California Gardening Guide
Month of July
July is the month when gardening comes almost to a complete standstill. It's a good time to browse through seed catalogs in preparation for August seed planting. You could almost take the month off if it wasn't necessary to water. It's just simply too hot to do much of anything.
Watering is the major chore from now until Fall. Except for some California natives and a few other drought tolerant plants, everything in the Southern California garden needs regular watering. With the hot dry weather, it's time to look at your watering practices. Irrigate thoroughly, long and deep but not frequently. Too frequent irrigation encourages roots to grow close to the surface where the soil drys rapidly and is subject to the extremes in temperature. Use sprinklers, soakers or drip systems, a thumb clamped over the end over of the hose is not going to cut it. If you water less frequently but for longer intervals, you force the water deeper in the soil where less will be lost to evaporation while encouraging deeper root growth.
Another way to cut back on water and keep roots cool is to mulch your garden heavily, covering the soil two to three inches deep with organic material. One free source of mulch is shredded tree trimmings. Check with a local tree trimmer. Many tree professionals are happy to drop off a load of shredded material in your driveway (it saves them the dumping fees). Dried grass clippings also make a great free mulch. It's particularly important to water long, deep and infrequently (remember... frequent shallow watering should be avoided) when you mulch because you need to penetrate the mulch layer but once soaked, the layer also slows down the evaporation loss.
Once the watering is done, don't quite hang up those gloves yet; there's still some planting that can be done and a few things in your garden that need some special care this month.
If you didn't plant tuberous begonias in the Spring, you can now find them in bloom at dig-your-own and specialty nurseries.
Continue to fill your vegetable beds. It's not too late to plant bean, corn, cucumber and summer squash seeds.
- Bougainvillaeas less than three years old should be watered regularly. Pay particular attention to newly planted specimens. Stop watering established plants (over three years old) at this time. There is no need to ever water any bougainvillea that has been in your garden five or more years; These plants are the most drought resistant around. Bougainvillaeas are not heavy feeders so little fertilization is necessary.
- Protect bromeliads from burning during the hot weather by making sure they have enough shade. This can be done by placing them under shade cloth. Now is a good time to propagate bromeliads by cutting off pups when they are one-third to one-half the size of the mother plant. Keep plants clean of spent blooms and dead leaves.
- Mulch around camellias to keep their roots cool. This is about the time for camellias' third and last feeding. The rule of thumb is to feed camellias six to eight weeks after the last blooms fall. Feed again six to eight weeks later, then one more feeding six to eight weeks after the last. A acid fertilizer is best but avoid over-fertilizing, as camellias are not heavy feeders.
- This is the time of year when cymbidiums produce more pseudobulbs and leaves. The quality and number of blooms these terrestrial orchids produce next winter depends in part on good summer care. Continue to feed with a high nitrogen fertilizer. Although cymbidiums shouldn't be soggy, don't let the roots dry out. These plants should be in semi-shade throughout the summer. A frequent mistake is to keep cymbidiums in too much shade. Black marks on the leaves and pseudobulbs indicate fungus problems. Fungus won't kill the plants but they won't bloom as well.
- When the flowers of most fuchsias fade, they fall off the plant but they leave behind their seed pod. Pinch off these seed pods (often called berries). This will encourage the plant to keep blooming. Misting can help keep plant cool in summer heat. Avoid over-watering. Keep roots damp but not soggy. Continue regular feeding with high phosphorus fertilizer for buds and bloom.
- Grass lawns
- When figuring out your mowing schedule, remember that grasses grow at different rates throughout the year. The key to good mowing practices is to mow higher in warm weather and to mow less often when the roots are growing more slowly.
Cool-season lawns such as fescue, bluegrass, and perennial ryegrass are growing slowly now, so they need less frequent mowing. Perennial ryegrass and bluegrass should be cut at about 2 inches. Tall fescue should be cut a little higher, 2 to 3 inches. Remember these grasses grow slowly during the summer so little or no fertilizer is needed.
Warm-season grasses such as bermudagrass, St. Augustine and zoysia are growing at their fastest now; they thrive in the warm summer heat. This means they need more frequent mowing. Bermudagrass and zoysia should be cut short, 0.5 to 0.75 inches. Cut St. Augustine to 2 inches. All warm season grasses should be watered deeply and infrequently to encourage deep root growth. Feed warm season grasses every six to eight weeks during the growing season. Careful about over feeding or you could spend your summer behind your lawnmower.
- After hydrangea flowers have faded, cut back each stalk to two buds. New wood will spring from these to bloom next year. On young plants, do not cut back any green stem that haven't bloomed yet for these will bloom next year.
- Irrigate 2-3 times a week. Make sure water is penetrating at least one foot below the surface. Mulch to maintain even moisture and keep roots cool. To control mites and clean leaves, wash foliage with a strong spray of water. Do this early in the morning, so the leaves dry quickly. Continue with regular feeding and in addition sprinkle a cup of alfalfa meal (available at feed stores) around each bush.
- Tuberous Begonias
- If you planted tuberous begonias in the spring they should be in full bloom now. They are heavy feeders so feed them regularly. Let them dry out between watering and remove spent blossoms.
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Last update: Thu, Feb 25, 1999.