Evergreen fern as a groundcover

Our most robustly evergreen fern, Christmas fern, associates well with evergreen sedges in shady gardens. Christmas fern (Polystichum acrostichoides) is a mid-sized fern with leathery foliage. If you can get it to grow in a dense mass it can be quite weed-suppressing (see photograph below). It is far more likely to reward you if it is grown in a rich, loose soil full of organic matter. Loose organic soil requires some work to establish and maintain in urban gardens, where heat and non-native earthworms breakdown organic matter with unnatural rapidity. Christmas fern will grow, and even thrive, in less accommodating soils but it will be slow to knit itself into a ground-covering mass. Look at the photo of wild Christmas fern growing in a woodlot – it has colonized an old, decaying log, thriving on the moisture and organic matter in the decaying wood, but it hasn’t moved into the surrounding soil. This picture was taken in mid-December. Christmas fern fronds used to be gathered for Christmas flower arrangements.

Christmas fern in a garden, with big blue hostas.
Christmas fern growing on a decayed log in a woodlot.

By the end of winter, the fronds are lying flat on the ground, making way for the new croziers, which start to unfurl very early. The new growth is a fresh, lovely green.

Fresh new growth of Christmas fern.

There is another evergreen fern in the genus Polystichum which is also native to Ontario, Braun’s holly fern (Polystichum braunii). This one is much less common. I have only seen it in the wild a couple of times, both times on the Niagara Escarpment near Owen Sound. I don’t know it well enough to understand what it might really want in a garden, but its distribution suggests it likes limestone or neutral soil and cool sites. Nevertheless, a Braun’s holly fern grew for many years in my mother’s Toronto garden until a neighbour’s construction project put and end to it. Braun’s holly fern has brown and fuzzy croziers.

Both Christmas fern and Braun’s holly fern are available at nurseries and garden centres that stock ferns. Their evergreen nature makes them justifiably popular with gardeners.

Braun's holly fern in city garden - unfurling croziers.
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Published by

Trish Murphy

Artist: botanical, still life, and natural history illustration. Garden designer: native plants and naturalistic gardens