EVERGREEN FERNS FILL SHADED NICHE

Planting ferns in shaded areas where flowering species are unable to

survive is a good solution for local gardeners in wooded sites, especially in

microclimates towards the coast that are dominated by redwoods and firs. But

ferns will grow in other places, too, as long as we meet their cultural needs.

Wannabe gardeners who live in new construction where overhead shade may be

an unknown commodity may have to wait years for trees to mature before they

can plant a woodland garden, yet they can often find a suitable spot for

ferns.

The north sides of structures, for instance, lie in shade as do areas along

east-facing walls where taller shrubs might filter afternoon sun. Broad

overhangs won't allow sun-loving species underneath, but ferns thrive in this

kind of shade.

Try to stay away from planting ferns under native oaks, however. It's a

fallacy to think that their protective canopies fit the bill for any

shade-loving plant. Ferns may come to mind, but, in general, they require too

much moisture for such a planting area. The ground under the oak canopy has to

be reserved for natives and Mediterranean species that can get by with little

or no summer water -- this is the infamous dry shade that poses so many

planting dilemmas for local gardeners.

Look instead to more hospitable areas, and not always in deep shade. Not

all ferns insist on continuous dim light. A few species tolerate some sun for

part of the day. Likewise, don't think that you need wet ground year-round.

All ferns require moisture to thrive and many grow naturally near water, but

most are intolerant of excessive wetness, although they still require fairly

high humidity.

A few ferns, such as the common bracken fern (Pteridium aquilinum) are too

invasive for the home garden. Bracken may look lovely along roadsides, but it

spreads so fast that its invasiveness is considered weedy.

With the wealth of nurseries in Sonoma County, there is no shortage of

opportunities to find evergreen ferns for the garden. Rita and Michel Ter

Sarkissoff list over two dozen places to buy shade plants in their ''Guide to

Sonoma County Nurseries.'' Some of the best for ferns are Sonoma Horticultural

Nursery south of Sebastopol, the Weekend Gardener in Monte Rio, and Cottage

Gardens in Petaluma.

Holly fern Variegata (Arachniodes simplicior) Where winters are frost-free,

this 1- to 2-foot fern remains evergreen. It boasts an attractive yellow

stripe along the central midrib of broadly triangular, glossy green fronds.

Deer fern (Blechnum spicant) Areas near the coast with partial shade and

near-constant moisture support natural colonies of this small fern, which

seldom exceeds 18 inches in height. Use it in rock gardens or in borders in

semi-shade as a companion to perennials where there is excellent drainage. It

benefits from constant shade in summer when planted in warmer interior

valleys.

Wood fern, shield fern (Dryopteris) This is one of the toughest groups of

ferns and one of the few that change color with the seasons. Young, lacy

fronds of autumn fern (D. erythrosora) carry coppery pink tones in spring

before they gradually green up and glisten in summer. The species is also

called Japanese red shield fern because of the reddish-hued sori on frond

undersides, that is, the scale-like coverings that protect clusters of spores.

Autumn fern reaches about 18 inches tall, 12 inches wide. Grow in semi- to

full shade.

Licorice fern (Polypodium glycyrrhiza) Common in wild, shaded areas of

Sonoma County and northwards along the coast, this spreading fern looks

something like a foot-tall sword fern. Lacking adequate water, it becomes

dormant in summer. To keep it evergreen, amend soil heavily with compost and

provide plenty of mulch and afternoon shade.

Leathery fern (Polypodium scouleri) A Sonoma County and West Coast native,

this little 6-inch fern grows in clumps on rocks and at the base of trees not

far inland from the coast. Plan to use this species in small areas only.

Western sword fern (Polystichum munitum) Anyone who has visited a redwood

forest has seen this stately, deep green fern as much as 4 feet tall. In most

garden situations, it remains smaller when fronds that begin to show brown

areas are trimmed away. It survives summer drought in nature where roots have

access to deep moisture, but in the garden it depends on regular irrigation to

look its best, especially for the first few years after planting.

Because it easily tolerates dark shade, sword fern is beautifully displayed

as a focal point in a woodland setting, but individual plants should be spaced

several feet apart and never should be crowded. Lower-growing, lacier ferns

make flattering companions, as do creeping groundcovers such as our native

ginger (Asarum caudatum), the more delicate sugar scoops (Tiarella trifoliata

unifoliata), and various heucheras.

Soft shield fern (Polystichum setiferum) This European relative of the

western sword fern is lighter green and lacier, its fronds broader at the base

and more triangular in shape, but it often grows just as tall as its West

Coast cousin. Many and varying cultivars exist, all of which should do well in

local gardens.

Leatherleaf fern (Rumohra adiantiformis) Good in cut-flower arrangements,

fronds of this species are what most people associate with ''fern.'' It is a

rather tender species that may not survive inland during cold winters, but

should do well in gardens along the coast.

Rosemary McCreary, a Sonoma County gardener, gardening teacher and author,

writes the weekly Homegrown column for The Press Democrat. Write to her at

P.O. Box 910, Santa Rosa95402; or send fax to 521-5343.