Ferns are tough and adaptable despite their fragile appearance. There are many varieties that are hardy to zone 3, making them very useful in our northern landscape.
They vary in textures; lacy to coarse. They are useful in front as well as the back of the border as heights vary from .30 – 1.2 m. Most are various shades of green but others have silvery foliage or interesting coloured stems.
Hardy ferns grow best in rich organic soils with adequate moisture and shelter from the hot afternoon sun. Some ferns will grow in increased sunlight provided they are growing in a moist soil. Once established, some will even tolerate very dry shade.
Ferns spread by rhizomes or underground stems. Some varieties have vigorous rhizomes and can spread into a larger colony. Some of these, like the ostrich fern, Matteuccia struthiopteris, can become invasive if given ideal growing conditions. I have this planted on a clay bank with periwinkle and do not find either invasive because of the tougher location.
Most ferns have short rhizomes and develop into a well-behaved centralized clump.
Amend the soil with plenty of organic matter, such as peat moss or compost at planting time. Water regularly and deeply. Plants will benefit from a mulch of fir bark mulch or compost every spring. A layer of chopped leaves before winter will help the plants overwinter. They are shallow rooted and will not tolerate foot traffic.
Ferns readily lend themselves to containers. One container, three different ferns and you will receive compliments galore; it doesn’t get any easier than that.
Bring it up a notch and add white impatiens for elegance or jazz it up with a mix of pinks and purples. In the fall plant the ferns into the garden or protect the container from frost by digging into the ground or mounding with straw or leaves.
Once you start growing ferns you will discover how unique and adaptable they are. The leather wood fern, Dryopteris marginalis is very tough and will grow in dry shade. Its dark blue-green sturdy fronds are often used in bouquets.
The cinnamon fern, Osmunda cinnamomea, has very upright, showy fronds that mature to a cinnamon-brown colour. They prefer moist to wet soil in sun or shade.
The Hart’s-tongue fern, Phyllitis scolopendruim is deer and rabbit resistant, heat tolerant and will tolerate our alkaline soil. I like its unusual fronds.
Another striking fern is the regal red lady fern, Athyrium nipp. Regal Red, because of its colourful violet red fronds with contrasting bright silver edges.
It is easy to design shade gardens with ferns because they go so well with hostas, astilbes and brunneras. They look best in a natural setting with shrubs, tree stumps, logs or boulders and are also useful for covering up the dying foliage when planted in combination with spring bulbs.
Jean Atkinson is a horticulturist with Richbar Golf and Garden and a regular Observer columnist.