Not only do lawns need less mowing and hedges need less shearing; they also need less water. Decreased temperatures and increased humidity limits evapotranspiration (evaporation of moisture from leaf surfaces) and vascular activity (which brings moisture to the leaves in the first place). Lawns can drown if watered as generously and frequently as they were in summer. Fortunately, the same weather conditions that diminish their demand for water also inhibit fungal diseases like mildew and rust.

Ideally, pruning and shearing of hedges should have been done in late summer when there was still enough time for new growth to mature and "blind-out," which means that it stops growing and produces a dormant closed bud at the tip of each new stem. Frost-sensitive plants pruned too late will produce tender new growth that does not have enough time to blind-out, so is consequently more sensitive to frost. This same sort of growth on tougher plants may not freeze, but is more likely to turn yellowish than blinded-out growth.

If pruned even later than too late, new growth will probably be safe from frost because it will not appear until spring, after the last frost. This might be fine for lightly sheared hedges that are not much fun to maintain anyway, but not so good for plants that are pruned more aggressively. If they look hacked, chopped or bare, they will stay that way for a while.

Every species goes dormant at a particular time. Many plants native to California might be dormant long before plants from other areas. This is because natives are adapted to the locally arid summers, so prefer to finish their growth during spring while things are still a bit damp. Consequently, coast live oaks pruned in late July will probably not start to produce new growth until next spring. Mayten trees pruned at the same time should already have a few inches of new growth on them by now. Scheduling pruning for the various plants in the garden can be tricky when they all are on their own schedule.

Deadheading (removal of fading flowers) becomes less necessary in autumn because there are simply fewer flowers. Even plants that bloom all year produce significantly fewer flowers as weather gets cool. There are actually only a few plants that bloom primarily or more profusely in autumn or winter. Fortunately, most of the few flowers that bloom last much longer as a result of the same cooler and damper weather. Camellias and chrysanthemums are two of the exceptions that rot if it rains too much.

The only thing that does not slow down in autumn is the need to rake leaves. Just as different plants go dormant at different times, they also drop their leaves at different times and at different rates. Leaves need to be raked off lawn and ground cover that might otherwise be shaded out. Leaves should also be raked off pavement that might otherwise be stained by tannins.

Flower of the Week:
air plant

The "Spanish moss" (Tillandsia usneoides) that hangs from large Southern live oaks in the South is neither Spanish nor moss. It is an American bromeliad related to the diminutive houseplants known as air plants, of which Tillandsia ionantha and T. aeranthos are popular species. They are epiphytes, which means they naturally grow without soil, on bark or in leaf litter that collects in the crotches of tropical trees. This is why air plants are quite happy mounted on plaques of bark or coarse wood. They only need occasional misting.

The grayish-green 1 ¹/2- to 2-inch long leaves of T. ionantha are arranged in compact rosettes, the centers of which turn somewhat red just prior to the appearance of the small, tubular purple flowers. The similarly colored flowers of T. aeranthos are less tubular, and emerge from pink bracts. Air plants are not grown in pots and are only rarely found in nurseries. They are more often found at craft fairs that include horticultural items.

Horticulturist Tony Tomeo can be contacted at 408.358.2574 or at LGHORTICULTURE@aol.com.