What to do in your Northern California garden in July
Mediterranean fan palm (Chamaerops humilis) is the best type for growing in containers, says palm specialist Jason Dewees of Flora Grubb Gardens. It’s drought tolerant and easily trained into a single trunk, plus it tolerates temperatures as low as 10° and is available in many sizes. Other choices include the pindo palm (Butia capitata) and Chamaedorea radicalis ― both feather palms ― and the fan palm Trachycarpus wagnerianus.
Keep your vegetable plot healthy this summer by planting flowers nearby that attract beneficial insects. Good options include buckwheat, coreopsis, cosmos, goldenrod, marigolds, Queen Anne’s lace, sunflowers, and yarrow.
Plant natives for late summer. Try one of these fast-growing native vines, recommended by Kathy Crane ― owner of Yerba Buena Nursery in Woodside ― for late summer and fall interest: Western virgin’s bower (Clematis ligusticifolia), which produces masses of white fluffy seeds and grows in the shade; and sun-loving, flaming red California wild grape (Vitis californica ‘Roger’s Red’). Crane also suggests reddish orange California fuchsia (Zauschneria californica), a native perennial that’s an important late-summer food source for hummingbirds.
Plant a showy coleus 'Henna', a striking new coleus, is a must-have for the summer garden. It grows 2 feet tall and 16 inches wide, and can fill a medium-size pot all on its own. But in lightly shaded beds and pots, its scalloped leaves ― splashed with copper and lime ― pair well with trailers such as chartreuse Lysimachia nummularia 'Aurea' or Ipomoea batatas 'Marguerite'. Grow it beside bronze Carex flagellifera 'Toffee Twist' and terra-cotta-colored calibrachoa. Pinch off flower spikes as they develop, and water regularly through the warm months.
For a healthy lawn, mow more frequently now that grass is growing actively, cutting no more than a third of the grass height at each mowing. Switching from a power to a reel mower will give a cleaner cut and reduce noise and pollution. For more info on reel mowers, check out People Powered Machines.
If you didn't already do so in spring, spread a 2- to 4-inch layer of organic matter (such as fine or shredded bark) over garden beds now to conserve moisture, cool plant roots, and discourage weeds. To prevent rot, don't pile it against stems and trunks.
Support fruit tree branches. Apple, peach, pear, and plum trees may be laden with fruit this month. To prevent limb breakage, use wooden supports to brace sagging branches. Also, regularly clean up and discard fallen fruit, since it might harbor diseases and pests.
When temperatures rise, adjust your automatic irrigation systems to water more often if needed and as your water district allows. Check container plants daily. Deeply irrigate mature fruiting and most ornamental trees every other week (every week in hot inland areas). Mature drought-tolerant trees need deep watering only once a month or so.
Summer pruning of new growth keeps wisteria under control and increases flowering next spring. To extend the height or length of the vine, select some of the new streamerlike stems and tie them to a support in the direction you wish to train the plant. Then cut back the rest to within 6 inches of the main branches.
Make sure the ground under the canopy of mature native California oaks gets no irrigation, because summer watering can kill these trees. The danger of root rot is greatest when you water close to the trunk. If you can’t keep the entire area under the tree dry, be sure no water gets within 10 feet of the trunk.