GARDENING : FLOWERS OF CANDYTUFT GLIMMER LIKE SNOW.

Byline: Joshua Siskin

It might just be that the whitest flowers in the world grow on the evergreen candytuft, Iberis sempervirens. This low mounding perennial, commonly used for edging walkways and planters, flowers this time of year when winter verges into spring.

The whiteness in these flowers is that seen on fresh, untrammeled snow that sparkles in the sun. It is the white of wedding gowns and newly painted picket fences. And yet it is a different white altogether - glittering, shimmering and luminescent.

Iberis (pronounced EYE-bur-is) is a genus that comprises about 30 plant species, all of them native to southern Europe or the Mediterranean. Iberia in fact, is a name sometimes used to describe the large peninsula that comprises Spain and Portugal. The evergreen character of this particular candytuft is indicated by its species name, sempervirens; in Latin, ``semper'' means always and ``virens'' means green. This species name is also found in the case of the Italian cypress, the classic columnar evergreen tree that bears the Latin name Cupressus sempervirens, or evergreen cypress.

Evergreen candytuft is one of the most carefree perennials for the sun garden. Given well-drained soil, a weekly soaking will be all the water it requires. If the plant is grown in the ground, fertilization may be completely overlooked without consequence. In containers, it will respond to any complete fertilizer - that is, any fertilizer that contains nitrogen, phosphorus and potassium.

Evergreen candytuft appears on lists of plants that are purported to be resistant to slugs. Although the snail gets most of the publicity where pestiferous mollusks are concerned, the slug (which looks for all the world like a snail without a shell) is actually a far more difficult critter to control, once it gains a foothold in the garden. For example, the same rough mulch - consisting of shredded tree prunings - that controls snails makes a superb habitat for the proliferation of slugs.

According to Patricia Taylor, author of ``Easy Care Perennials and Easy Care Shade Flowers,'' slugs will stay away from plants with gray, fuzzy leaves. Such plants would include the many artemisias, the gray-leaved yarrows or Archilleas, lamb's ears (Stachys byzantina), and rose campions (Lychnis coronaria). Incidentally, the pinks and reds of rose campions are as unforgettably brilliant as the phosphorescent white of the evergreen candytuft. Coralbells (Heuchera), foxgloves (Digitalis), Lenten roses (Helleborus), and ``Moonbeam'' coreopsis are also on the list of slug-resistant plants.

If you enjoy growing flowers from seed, consider the annual candytufts. The rocket candytuft (Iberis amara) has fragrant white flowers on foot-long stems. The globe and dwarf candytuft cultivars (Iberis umbellata) are not fragrant, but compensate for this deficiency with colors that range from deep red to lilac, lavender and pink.

The thought of growing a vine with fragrant spring flowers has romantic appeal. The idea is to plant such a vine at the base of a gazebo or an arbor, where people sit, so that they can enjoy the first warm days of spring while basking in the delightful scent of flowers growing overhead. Of course, there is nothing wrong with growing such a vine on a trellis that arches over your front steps, so that you can enjoy a fine fragrance when entering or leaving your house.

The fragrant flowering spring vine of choice is pink jasmine (Jasminum polyanthum). This vine is blooming now all over town. In truth, the flowers of pink jasmine, once open, are white. The plant is called pink jasmine owing to the fact that the flower petals are pink on the outside; before the flowers open, they actually appear more pink than white.

Proper maintenance of established pink jasmine includes shearing it back significantly once its flowers have faded. If this is not done, it will grow a plethora of billowy shoots which will shade out the interior of the plant, resulting in unsightly brown leaves. These dead interior leaves cling stubbornly to the plant for many months, and must be pulled off one by one. Typically, the interior shoots with brown leaves form the main body of the plant. You have to resist the temptation to cut out these main shoots - if they are severed, the plant will have to start growing, from ground level, all over again.