Ferns are ideal for shady gardens

Richard Bogren | 4/12/2017 7:36:10 PM

LSU AgCenter Horticulturist

(04/14/17) I don’t know about you, but as the hot weather of summer arrives, I’d much rather work in shady gardens than sunny ones. I’ve heard gardening in the shade called “challenging,” but it’s really no different than gardening in the sun. When the proper plants are selected for shady areas, the results can be beautiful and durable.

Many great plants for shady areas can be found among the ferns. The different species range in size from under a foot to as much as 3 feet tall. The leaves of ferns are called fronds and provide the primary ornamental feature of the plants. On ferns that are commonly used in landscaping, the fronds are generally finely divided and delicate in appearance. They contrast beautifully with coarser-textured shade plants such as hostas, aspidistra, fatsia, gingers and aucuba. Holly fern is an exception as its fronds are coarser than most ferns, giving this plant an almost shrubby look.

Ferns do not produce colorful flowers. Their attributes are subtler but no less beautiful to the discerning eye. It would be unfair to say that ferns are just green; they come in many shades from chartreuse to deep olive, and some produce fronds that are tinted with red or have silvery variegations. Ferns often possess a grace of form and movement that is unique among garden plants (except for maybe ornamental grasses).

Some ferns we can plant in the landscape are evergreen, and some are deciduous. Deciduous ferns such as the wood fern (Thelypteris kunthii) and royal fern (Osmunda regalis) lose their fronds in the winter and go dormant. Some of the evergreen ferns may suffer damage or lose their fronds during severe winters, but more often they retain their foliage throughout the winter season. If they are frozen back, they reliably return from their roots.

One of my favorite things about ferns is that they are so easy to grow. Generally not prone to any major insect or disease problems, ferns are plants you can generally make happy with minimal care.

Ferns will grow best in areas that receive one to four hours of direct sun or dappled light during the day. Morning sun is greatly preferred. Definitely avoid hot, dry areas that receive several hours of direct sun in the afternoon or areas that receive sun all day. If you want a fern-like plant for sunnier areas, you could plant yarrow (Achillea millefolium) or asparagus fern (Asparagus densiflorus Sprengeri, which is not a true fern).

The majority of ferns do best in a consistently moist soil. They thrive our state because of our high rainfall and humidity. Of course, during dry periods you need to water landscape ferns. As with all plants, there is no timetable or schedule that you should follow for watering. Watering is done when the plants need the moisture based on the amount of rainfall that has occurred and how hot the days are. Mulching a fern planting with your favorite mulch, such as leaves, dry grass clippings or pine straw, is highly recommended to conserve soil moisture and reduce weeds.

When preparing a planting site for ferns, thoroughly turn the soil and remove any weeds. Spread a 2-to-3-inch layer of organic matter (compost, rotted manure or peat moss) over the area and dig it in. Make sure it is well blended with the soil in the bed.

Shady areas often occur under trees, and it is entirely permissible to create planted areas under trees that incorporate ferns and other shade-loving herbaceous perennials, ground covers and shrubs. Respect and minimize damage to the root system of the tree, however. Avoid adding more than 2 or 3 inches of fill to the area, and do not sever any roots over an inch in diameter. When turning the soil, use a turning fork because it will be less damaging to roots than the blade of a shovel or spade.

In February or early March, cut back the dead fronds of deciduous ferns and prune away any cold damage done to evergreen ferns. Get this done before the new fronds grow up among the dead ones, and it will be easier not having to work around the new growth.

As time goes by, many ferns will grow into a fairly large clump. Should you need to divide your ferns, the best time is in late winter or early spring, around February. Ideally, ferns should be divided before the new, spring fronds have made much growth. Keep them well watered while they get reestablished.

Most nurseries carry a nice selection of ferns. When visiting a nursery, ask where their shade area is, and that’s generally where you will find the ferns along other plants that like the shade and make good companions for the ferns.

Some excellent ferns for use in the landscape include Southern maidenhair fern (Adiantum capillus-vernis), holly fern (Cyrtominum falcatum), leatherleaf fern (Rumohra adiantiformis), Christmas fern (Polystichum acrostichoides), royal fern (Osmunda regalis), autumn fern (Dryopteris erythrosora, known for its coppery red new fronds), lady fern (Athyrium filix-femina), wood fern (Thelypteris kunthii), lace fern (Microlepia strigosa), Japanese painted fern (Athyrium niponicum Pictum) and sensitive fern (Onoclea sensibilis).