IN THE GARDEN AFTER RAIN SPELL, SWEET SMELL.

Byline: JOSHUA SISKIN

There is no scent on earth that can rival that given off by sycamore trees after a rain. I was reminded of this fact after last week's relatively short storm ended a rather long stretch of drought.

Sycamore fragrance is fruity, spicy, nutty, woodsy and just plain sweet. It is more subtle than the stronger fragrances of orange blossoms, gardenia flowers or jasmine. Yet these more powerful scents make you step back soon enough; their strident sweetness has its limits. Unlike the overwhelming perfume of flowers, sycamore fragrance should be breathed in slowly at one's leisure.

The much-maligned California sycamore, a host for insect pests and fungus diseases whose leaves are more often brown than green, redeems itself in spades whenever it rains. If you are searching for authentic Valley experiences, you would probably put inhaling the scent of sycamores after a rain near the top of your list. After all, nearly at the moment that time began, California sycamores lined the banks of ancient rivers that coursed through what was once a wilderness in what today is known as the San Fernando Valley.

There are other fall and winter fragrances, many coming from plants not regularly seen here, that Valley gardeners may wish to note. Some of these plants hide their fragrance for much of the year but express it unreservedly after a rain.

Sweet box (Sarcococca humilis) is a wonderful ground cover for the shade with shiny green leaves and black fruit; Sarcococca ruscifolia is a stout shrub, also for the shade, with red fruit. Both have mellifluous white blossoms during the winter.

Common witch hazel (Hamamelis virginiana) is a large shrub of amorphous growth habit that produces highly fragrant yellow flowers in the fall. Its leaves also change color - to orange and yellow - this time of year. Winter daphne (Daphne odora) is perhaps the most fragrant and most perplexing of winter bloomers. The mesmerizing fragrance and naturally dapper mien of this medium-size shrub are diminished by its capriciousness in the garden. It can live for many years or only a few, show perfect health one day and then die practically overnight. Imperfect soil drainage is most likely the culprit should this plant die within its first few years in the garden.

Several plants from Australia proffer scents that make a stroll through the garden after a rain a memorable amble. Chief among these, in both size and smell, is the lemon-scented gum (Eucalyptus citriodora). Towering up to 60 feet or taller, this tree with the alabaster trunk is forever fixed in the minds of those who may have once lived in its vicinity. Its lemon fragrance is inescapable, especially after a rain.

Another pungent, if lesser-known Australian arboreal specimen, is the so-called peppermint tree (Agonis flexuosa), with bulging biceps branches and a somewhat weeping growth habit. The Australian peppermint bush (Prostanthera rotundifolia) has mauve flowers; when happy in well-drained soil, it can grow to 6 feet. Brown boronia (Boronia megastigma), also from Australia, has bell-shaped and bronze-colored winter flowers with an intoxicating, orange spice aroma all their own.

Sweet acacia (Acacia farnesiana) is native to the American Southwest and produces scads of honey-scented, yellow puffball flowers in the winter. Its leaves are also unusual, consisting of dozens of delicate, feathery, blue-green leaflets. As if its flowers and leaves were not sufficient recommendations for granting sweet acacia a place in and around our gardens, it also possesses wicked thorns, making sweet acacia the obvious choice for a living, drought-tolerant security fence - should you require one.

TIP OF THE WEEK: Because of the resin that coats their leaves, rockroses (Cistus species) are among the most fragrant dry-climate shrubs. Native to the Mediterranean, these shrubs require little if any water and produce fetching, crepe-paper blooms in pink, magenta, purple or white. The rockier the soil, the steeper the grade - the better they grow. Prune lightly, if at all, and be prepared to replace them after five or six years in the garden.