IN THE GARDEN PERFECTLY WATERED CONTAINERS.

Byline: JOSHUA SISKIN

One of the most challenging tasks for summer gardeners is maintenance of plants growing in flowerpots and other containers.

Success with container plants is more predictable with larger containers, since less watering is required. The more often you have to water a plant in a container, the more likely you are to have problems, as missing a single watering could put the plant under life-threatening stress.

Plants in small containers may require daily summer watering, while plants in large containers (20-inch diameter and larger) can remain vibrant for as long as 10 days between waterings. Yet frequent watering can also lead to fungus problems as a result of standing water in the saucer underneath, which may never allow soil at the bottom of the container to dry out.

And the more often you water, the more often you need to fertilize. For this reason, it is best to spread slow-release fertilizer on the surface of the soil in which container plants are growing.

Slow-release fertilizer need only be applied two to three times per year. When the fertilizer granules are no longer visible on the soil surface, it is time for another application. Growing container plants in shade or partial sun is much easier than growing them in full sun. This is even truer on concrete pool decks where the splash of chlorinated water, combined with reflected heat from the concrete surface, makes it almost impossible to grow lush potted specimens. Reflected heat not only pummels the foliage of pool deck plants, but it cooks the soil in their containers as well.

One of the complaints of people who grow plants in containers is that the water draining through them stains the deck, patio or flooring beneath. The Jardinier is an invention that has solved this problem. With the Jardinier, no water runs out through the bottom of the pot.

The Jardinier is a flattened cylinder with holes in the roof and a piece of PVC plastic pipe vertically attached. The Jardinier is placed snugly in the container and covered with soil. Planting is done in the usual fashion.

In order to water your plants, you pour or hose water into the vertical pipe that reaches just above the soil surface. The water fills the cylinder and - by evaporation through the holes in the roof of the Jardinier and capillary action - it moves up through the soil in the container until it reaches the roots of the plants above. For large pots that contain a shrub or small tree surrounded by flowers, two-tiered Jardiniers are available. Extend a dipstick into the PVC pipe to determine the level of water in the Jardinier.

The amount of water you need to apply to container plants will be reduced through the use of Jardiniers. Jardiniers are also useful for vacationers who want to fill up their pots just before traveling, since the slow evaporation through the cylinder will keep the soil moist.

Among the plants that do best in containers are small palms such as Mediterranean fan palm (Chamaerops humilis) for sun, dwarf pygmy date (Phoenix roebelinii) for partial sun, and lady palm (Rhapis excelsa) or bamboo palm (Chamaedorea Seifrizii) for shade.

Other container standouts include: the bush bougainvillea 'Raspberry Ice,' with red-tipped variegated foliage and magenta flowers; the modest-size Magnolia grandiflora 'Little Gem'; the tropical, umbrella-leafed Tupidanthus calyptratus; succulents and cactuses of every description.

TIP OF THE WEEK: Most container plants do not receive an equal amount of light from every direction. To keep your plants balanced and not leaning in one direction, rotate them a quarter turn every two weeks.