IN THE GARDEN GARDENIAS THRIVE ONLY IN THE RIGHT CONDITIONS.

Byline: JOSHUA SISKIN

Q: Can you tell me why the buds on my potted gardenias seem to dry up and fail to open? The plants seem to like more water than I expected in order to maintain healthy-looking foliage.

Frank Caramelli,

Tarzana

A: Gardenias are among the most puzzling plants for Valleyites or anyone else to grow. Of every 10 gardenias I see in local gardens or, like yours, in containers, at least nine look pathetic; leaves are yellow or burnt, growth is spindly, and the plants as a whole look ready for the compost heap.

Whenever I have trouble growing a certain plant, I learn about its habitat. If I can get to know its natural environment, I can attempt to duplicate that environment in my own garden. Gardenias come from southeastern China, where the soil is acidic and the air is humid. Hmm ... exactly opposite from the alkaline soil and dry air of the Valley. What's a gardener to do?

Gardenias like their soil constantly moist but never wet and never dry. The experts recommend mixing regular fast-draining topsoil with a good compost, organic soil amendment or potting soil. Then, from March through November, apply an acid fertilizer together with iron chelate once a month. Gardenias also do best with four hours of bright ambient light and should be kept out of direct sun - but also out of the shade. A morning sun exposure or a filtered afternoon sun exposure work best.

The bud drop you describe can be the result of too little or too much water, too little or too much sun, or incorrect soil pH - in short, just about anything.

One final no-no: Never transplant a gardenia from one garden spot to another. Once a gardenia is in the ground, it should be left there permanently; moving it will almost certainly result in its demise.

Q: I am looking for a garden patch to rent or have for no charge so I can grow my own vegetables. Do you know of such a place in Santa Clarita or San Fernando Valley?

Mary Bradway,

Santa Clarita

A: The Sepulveda Garden Center in Encino, at 16633 Magnolia Blvd., just west of Hayvenhurst Avenue, is the perfect place for you. You can rent a 10-by-20-foot garden plot for $20 per year, not including an $8 start-up fee. Be advised that there may be a waiting list. Call [phone].

TIP OF THE WEEk: After a good soaking rain, the best gardening practice is to stay out of the garden. Stepping on wet soil compacts it, and digging in wet soil can impair oxygen availability to roots for months to come.