FRUITFUL ADDITIONS TO YARD.

Byline: Joshua Siskin

The end of President George W. Bush's first week in office seems as good a time as any to discuss the other bushes - those we may cultivate in our back yards.

Now is the best time of year to plant blackberries and raspberries, which grow on bramble bushes. Botanically, the bramble bushes are closely related to roses. Not only do they have flower characteristics and thorniness in common, but the productivity of their new growth is short-lived as well.

Roses are cut back radically in order to stimulate new and vigorous shoots on an annual basis. Left unpruned, those same shoots that flowered so prolifically and luxuriantly last year will give few flowers this year. Better to remove all of last season's growth and generate entirely new shoots for another large, fresh crop of roses.

With blackberries and raspberries, the exhaustion of shoots and canes - following flowering and fruiting - is even more dramatic than in the case of roses. With roses, a cane can continue to sprout productive flowering shoots for years. In the case of blackberries and raspberries, once a cane has produced fruit it should be cut back completely, all the way to the ground. In essence, blackberry and raspberry canes exhibit a biennial habit of growth. The first year a cane develops, it grows as much as 10 feet, but shows nothing but foliage. The second year, it flowers and bears fruit.

After harvest, immediately remove all fruiting canes, and thin out and cut back 1-year-old canes, which will now put out side branches and so provide you with a maximum crop the following year.

Blackberries and raspberries should be grown on trellises. They must be protected from our dry summer heat and do best planted up against a north-facing fence or block wall with good ambient light. They demand a well-drained soil that should be cultivated to a depth of one foot or more prior to planting. Work in a 4-inch layer of compost or peat moss. Although blackberries and raspberries will produce with a minimum of fertilizer and water, they will yield significantly greater crops when minerals and moisture are in abundance. Mulching is highly recommended.

Blackberries and raspberries can be ordered bare root through local nurseries and through the Internet. A large variety of bramble berries is offered at www.myseasons.com. Among the raspberry selections you will find is the bababerry, a variety especially suited to our area owing to the fact that it does not require a cold winter to bear fruit.

TIP OF THE WEEK: After the rain, the soil level in large planter boxes, especially where soft soil mix has been used, often sinks down several inches. To prevent this from occurring, tamp down soil mix and tamp it again before planting. You really cannot over-compact the soil prior to planting. When you plant, just make sure the backfill is not too tightly packed in around the roots of your trees and shrubs.

Note: The number listed in last Saturday's column for High Country Gardens is the catalog's fax number. The phone number is [phone].

Garden Wonders

Have you grown a 50-pound pumpkin or a 20-foot sunflower in your yard? Have you discovered an unsual plant sprouting beside your house or planted one that has made you proud?

We want to know what's special or unusual about your garden. Write a brief note about what you've grown and how you did it, or call us with the information. Please include your name, address and a daytime phone number. Send this information to: Garden Wonders, L.A. Life, Daily News

P.O. Box 4200 Woodland Hills, CA 91365-4200

E-mail: [e-mail]. Fax: [phone]. Phone: [phone].

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