September to-do list for your garden

By Rebecca Jepsen
for the Mercury News
September 6, 2008

Bitter pit in apples is a common problem that shows up as small dark, bruise-like spots near the end of the apple. The condition is caused by a lack of calcium uptake by the fruit. To control, mix one tablespoon of calcium nitrate in one gallon of water and spray leaves of tree. This should be done in early spring just after bloom. 

Winter squash is ready to harvest when the stem begins to shrivel. Pick before the first frost; cure by letting it sit in the sun for at least 3 days, turn daily. Squash will keep for up to 5 months if stored in a cool dry place.

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 1/3 of the height off at any one time stresses the lawn leaving it more vulnerable to pests and disease.

Deep water trees twice during the summer, even when they are planted in the lawn. 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 everythreeto four weeks; young fruit trees need to be watered every twoweeks. 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

What to plant now

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

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

To find a list of cool season vegetables that do well in Santa Clara County, go to or call the hotline at 408.282.3105.

- Rebecca Jepsen, Santa Clara County Master Gardener.