Q. This fall I planted several beds of bulbs, mostly daffodils, iris, and tulips. Are there any herbicides that are safe to use on them?

A. There are only a few herbicides that can be used to control weeds on newly planted bulbs. Oryzalin (sold as Surflan and Weed Stopper), pendimethalin (sold as Penduluum and Pre-M), Treflan, Team, and XL are all preemergence herbicides (they do not kill established weeds, but do kill germinating weed seedlings). According to their labels they can only be applied 2-4 weeks after planting the bulbs. If weeds have already emerged then lightly cultivate the bulb bed before applying the herbicide. Be sure to irrigate after application. Dacthal and devrinol also carry labels for some bulb situations, but are not as easy to find on store shelves anymore, still many gardeners have not yet exhausted their supply of them.

The only postemergence herbicides that can be used after the bulbs and the weeds have emerged are the grass killers, like as Grass Getter and Grass- Be-Gon. There are no postemergence herbicides specific for broadleaf weeds that won't also hurt the bulb plants.

Q. Is it too late to plant a vegetable garden?

A. Several vegetables can still be planted in November including carrots, lettuce, onions, radishes, and spinach. Choosing the right variety is important for onions and garlic, but your favorites can be selected for the other vegetables.

Be sure to purchase intermediate day onion seed like Fresno or Stockton yellow, red, or early red. These varieties will form bulbs of good size and be ready to harvest in April or May. Almost any variety will do if you are only interested in scallions. Avoid onion "sets" that are available in most garden stores only because they are typically long day onions and will not form a bulb under CA growing conditions.

Garlic planted now will be ready to harvest in July. Supermarket types are typically "soft neck or non bolting" varieties called CA Early and CA Late. Elephant garlic with milder taste and larger size, is not a true garlic but a member of the leek family, however, it is grown just like garlic.

The size of garlic bulbs at harvest is directly related to the size of cloves used at planting. For maximum size plant only the biggest cloves from the outside of the largest bulbs. Choose a sunny location, plant cloves 1-2 inches deep with the pointed ends up, fertilize moderately but frequently, and keep the soil moist but not soggy. Garlic is approaching maturity when the tops start to die back.

Q. Five years ago I planted a peach, nectarine and a plum tree in my backyard. In the spring and early summer many of the leaves on the peach and nectarine tree were puckered, curled and distorted, and then they all fell off the tree. The plum tree leaves were fine. What causes this?

A. You are describing leaf curl, one of the most common disease problems for backyard gardeners. The good news is that it only affects the leaves and shoots of peaches and nectarines and it is easy to control. The bad news is that if left unchecked for several years, the disease gets progressively worse until fruit production decreases, branches get sunburned, the tree declines and needs to be removed.

To prevent leaf curl, treat peach and nectarine trees with a copper-based fungicide around Thanksgiving after leaves have fallen. A slurry of hydrated lime and copper sulfate (called a Bordeaux mixture) or a synthetic fungicide may be used. Just be sure that the spray compound contains at least 50% copper. If timed properly, a single spray will normally prevent the fungus problem. If it turns out to be a rainy spring a second spray is recommended at bud swell.

November 18, 1999