September to-do list for gardeners

By Rebecca Jepsen
for the Mercury News
September 4, 2009

Mosaic virus on squash and cucumber plants is spread by aphids and cucumber beetles. The disease causes leaves to become rough and mottled. Plants can be stunted, and fruit can turn whitish. It's best to remove and discard diseased plants; do not add them to your compost pile.

Leave grass clippings on the lawn when you mow. They provide nitrogen and help retain moisture. Mow lawn frequently. Cutting more than one-third of the height off at any one time stresses the lawn, leaving it more vulnerable to pests and disease.

Don't forget to deep-water trees, even as days turn cooler, until the rains begin. Use a soaker or drip hose around the drip line of the tree; let it drip slowly for two to three hours. 

Mature fruit trees should be watered every three to four weeks; young fruit trees need to be watered every two weeks. Some mature ornamental or street trees may not need any water, check the variety to be sure.

For our complete list of September gardening tips, click on www.master gardeners.org/tips/september.html.

What to plant now

Transplants: arugula, beets, Swiss chard, broccoli, Brussels sprouts, cauliflower, Asian greens, spinach, mustard and lettuce. Local nurseries should have a good supply of most of these.

Seeds: arugula, beets, carrots, lettuce, Swiss chard, fava beans, peas, onion, radishes, spinach and direct plantings of garlic and potatoes.

To find a list of cool-season vegetables that do well in Santa Clara County, go to www.master gardeners.org/picks/cool.html.