Gardening : Trees Do Best When Planted Now : Landscaping: Proper site selection is important, whether you’re planting for shade or ornamentation.

December through the end of March is the best time of the year to plant trees in California. These usually rainy winter months help young trees get off to a good start.

Even in drought years, which 1990 may turn out to be, new trees do best when put into the ground in winter.

That’s when they tend to be dormant, resting before a spurt of growth in the spring. Transplanting them from nursery pots now is less of a shock to them than at any other time.

Plant trees where you’ll feel the most proprietary about them--in your front or back yard.

If you have no room in your yard, remember that most cities will permit you to plant trees by the sidewalk, near the curb.

Just call the appropriate city agency, usually the Department of Public Works, for permit information.

Analyze the contours and dimensions of your yard, the total environment and its climate. Will a tree throw too much shade on your vegetable garden or your neighbor’s?

Could it liven up a boring corner? Keep your house cooler?

Don’t place a tree too close to your house because its roots could grow into the foundation or around water pipes and underground utilities.

Its branches could get in the way of overhanging eaves. A good rule of thumb is no closer than 8 feet for smaller trees such as Flowering Cherry, Hawthorne and Thotinia, and no closer than 12 feet for larger species like Southern Magnolia, Box Elder, or Red Flowering Horse Chestnut.

While some species of native California oak, such as coast live oak, valley oak and black oak are wonderful in large yards, remember that they don’t like to keep their “feet” wet, and the watering requirements of your lawn and flowers will do them in.

Don’t plant the giants, such as redwood, Norfolk pine, Monterey pine or blue gum eucalyptus, in a small back yard.

They are for landscapes far larger than the standard city lot. Keep in mind the fact that trees do grow, so don’t fall in love with a cute little potted tree at the nursery. It could be a 40-foot ash in 10 years.

If you live where the summers heat up, think seriously about planting a larger species of a low-branching tree on the southeast or southwest side of the house, where the sun shines the longest and hottest.

It will keep your home cooler and help reduce your air conditioning costs by more than $100 in a year. Yew, Japanese Zelkova and European hackberry are three beautiful shade trees that do a great job.

Water conservation is increasingly important in California, so you may not want to plant a thirsty species like eastern maple, willow or the flowering ornamentals.

Consider a drought-tolerant tree such as one of the many native species (Red Bud, Catalina cherry and coast or valley oak) or a Mediterranean (olive, laurel, Italian buckthorn), or a comparable climate tree, such as the New Zealand Christmas tree.

Trees are relatively care-free except for the first three years, when they need regular watering to get well established.

If rainfall during the winter planting season is normal, then you’re home free, at least for a few months.

In the drier months or in a dry season, new trees require 15 gallons of water once a week. Water deeply. Don’t just spray for a couple of minutes and think you’ve done it.

Adjust the pressure so that the hose trickles for 15 minutes to make sure the water saturates the soil and gets down into the tree root ball.

Deep watering will also prevent surface roots from developing. It’s these roots that can crack the sidewalk.

If there is less than normal rainfall during the rainy season, you will have to help the tree out. Give it 15 gallons every other week or so.

Watch your tree for signs that it needs water. Drooping leaves are a reliable indicator, but you can also test the soil with a water meter, and if the top 5 inches are dry, then get the hose.

There’s nothing wrong with removing a tree if it’s diseased, incurable, too old or injured. The only sin is not replacing it.

Put it out of its misery and start over. A healthy tree does the planet and your property values an infinitely bigger favor.

It will clean up to 50 pounds of air pollution each year and add at least 10% to the resale price of your house.

If you’re unsure about the condition of an existing tree, take a photo of it along with a few leaves to a nursery and find out.

If the diagnosis is terminal, replace it, but not before you check with the city to see what kind of permit is required. (In many cities, it’s a crime to remove a tree without a permit.)

Everyone outside of California thinks of the state as one big sun-tan parlor, but we who live here know that there are many micro-climates, often within a 2-mile radius.

Here are a few suggestions:

For shadier, foggier, and coastal areas: ficus, strawberry tree, New Zealand Christmas tree.

For sunnier, hotter climates: California pepper, olive, honey locust.

For windy yards or streets: melaleuca, Monterey pine, red flowering eucalyptus.

For neighborhoods where only an accent is required because of the homes’ unique architecture: flowering plum, evergreen pear.

For sidewalks with heavy foot and car traffic: ficus, eucalyptus (smaller species).

For overhead utility compatibility: bronze loquat, Bailey’s acacia, Chinese pistache.

For even more choices, consult Sunset’s Western Garden book, which has detailed descriptions of many different trees.

Narrow the field and then check with your local nursery to see which ones they recommend for your specific situation, and if they’re available.

Again, check with your city agency for requirements or restrictions for street trees. Call either the recreation and parks department or department of public works.

If you yearn for a leafy paradise of trees but the lots in your neighborhood are too small, seriously consider planting trees on the sidewalk, next to the curb.

Not only will they unify disparate architecture and obscure differing states of home repair, they will add a sense of community and privacy.

They’ll also help clean the air in high traffic areas and cut down on noise. Homes on a tree-lined street generally increase in value, anywhere from 10-25%, over comparable homes in barren landscapes.

Organize your neighbors to join in a cooperative venture and then work with the local tree-planting organization that is established in your city. To find out where the nearest group to you is, call California ReLeaf’s 800 number: (800) 873-3436.

The best tree to plant for the garden is a standard 5-gallon size, and for the street, a 15-gallon tree.

Nurseries stock trees in three sizes: 1, 5 and 15 gallon, based on the size of the container in which they’re displayed. They usually have a good, though limited, selection.

You can also order from tree farms, but while you can be fairly well assured that the trees in your local nursery are appropriate for the area, you’ll have to be more discerning if ordering from a large grower.

If you’re an impatient landscaper, you can special order larger, more mature box trees, but they’re expensive.

Trees are an important anti-pollution resource, so be kind to them, especially those planted on the sidewalks.

Don’t staple your organization’s poster on one. Don’t empty your used car oil or beer can in the soil or use the basin as a litter basket.

Back into a parking space a little more carfully when a tree is nearby. Tell a merchant how much you appreciate the tree outside his store--and that it could use a little more water. After all, that tree is helping extend everyone’s life.

California ReLeaf is a project of the Trust for Public Land, which intends to plant 20 million trees throughout the state by the year 2000.

Conserving Water

If you’re concerned about water conservation, worried about drought or are on water rationing, use “gray” water for your trees. This can be any household waste water that would ordinarily go down the drain: the warm-up water in your shower (collect it in a bucket), dish-washing rinse water or washing machine rinse water.

RESOURCE If you have any tree questions that your local nursery can’t answer, contact TreePeople at (818) 753-4600.