September: Santa Ana winds blow in, so brace trees, reduce fire threat and water, water, water
September can be too hot to think about fall planting -- or to do much of anything but water. Just remember that even if Santa Ana winds kick up the temperatures, the days are short and the sun is low, new plants can still thrive.
Wind in the willows
Santa Ana winds can cause plants to wilt temporarily because they pull moisture from leaves faster than the plants can replace it. Leaves most likely will perk up in the evening. If not, you may need to water.
Trees can be more susceptible. Winds can snap young trunks and break branches on even the sturdiest specimens. Make sure young plants are staked properly. Tie the trunk between two posts, about 6 inches to either side, with something flexible. It should be able to sway a little and build up strength. Strips of old bicycle inner tubes work well. On especially thin trunks, you may need more than one set of ties. Larger trees will need strong ties.
The denser the trees, the more likely they are to lose limbs or even topple. That makes September a good time to open them up with careful pruning of entire branches -- what some arborists call “lacing.” Don’t let tree pruners simply stub back branches, because the resulting flush of growth will be prone to breaking and those pruners will need to return sooner than you hoped.
Reducing the fire threat
Fierce winds also fan wildfires, especially near the coast. Cut back brush and weeds. Get under shrubs and trees and clean out deadwood.
Make sure everything of size -- even natives and drought-resistant plants -- has been thoroughly watered at least once this month. Watered plants are less likely to burn. The best way to water shrubs and trees is slowly and for a long time. Let the water trickle.
You may have already seen them. Those spiders will get even bigger in September, but don’t be too hasty to kill them. They may be catching nuisance bugs. If they build webs too close for comfort, knock the webs down with a hoe and the spiders will probably rebuild higher. They take down those webs almost every day and rebuild them each evening.
Make sure all dead flowers and hips (seed pods) have been removed and give the roses a light clipping early, then fertilize and keep plants watered. They will bloom in October or early November, when the weather is a little cooler, and the flowers may rival their spring counterparts.
Bulbs probably will begin arriving at nurseries in late September. Tuck them here and there in the garden, and they will deliver delightful spring surprises. Some also can be massed, though it can be a lot of work planting them. One exception: easygoing ranunculus.
The best bulbs for your special spots are the ones that will last from season to season in our warm climate. Many don’t, including tulips and other Dutch bulbs. Tulips and crocus need about six weeks of cooling in the vegetable bin of the refrigerator before being planted. These cold climate bulbs will last one season and should be treated as annual flowers.
If you want staying power, stick with amaryllis, baboon flower, calla lily, small-flowered daffodils and narcissus, Dutch iris, freesia, homeria, ipheon, ixia, ixiolirion, lachenalia, Leucojum aestivum, moraea, nerine, Scilla campanulata, sparaxis and watsonia. These can be left in the ground and, although they go dormant for the summer, they will return each fall.
Vegetables to try
If you keep the seed moist, many vegetables will quickly sprout in the heat. Some to sow now: beet, broccoli, Brussels sprouts, carrot, cauliflower, celery, endive, garlic, kale, kohlrabi, leek, head and leaf lettuce, onion, pea, radish, spinach, Swiss chard and turnip. Just about any of these can be put in as transplants later in the month.
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