For some reason I always seem to get along with those gardeners that collect ferns and I think it’s because they pay close attention to botanical detail, which is something that I greatly admire. Ferns are not just some nondescript aggregate of leafy greens that grow in the shade; they are wonders of plant form and come in many colours, including purple, white and reddish-orange. They can be found growing on every continent but Antarctica in both temperate and tropical climates and have been around for millions of years, as evidenced by fossils found right here at Kanaka Creek. So I thought I’d take you on an in depth voyage through the diverse world of hardy outdoor ferns.
Japanese Painted Ferns – There’s no better place to start than with the ‘least green’ fern I know, Athyrium niponicum var pictum or Japanese Painted Fern. These herbaceous beauties are a bit slow growing but really pop in the shade garden with their silver and purple fronds. ‘Pewter Lace’ brings even more silver to the forefront, ‘Ursula’s Red’ a broad band of wine-red, while ‘Godzilla’ is a larger cultivar.
Athyrium 'Pewter Lace', Athyrium niponicum var. pictum
Maidenhair Ferns – The Maidenhair ferns are a delicate looking family, with ebony stems starkly contrasted by iridescent lime green leaflets. Our native species Adiantum aleuticum eventually grows into a bold clump about 2.5’ tall and is very similar to the eastern species, A. pedatum; both are hardy to USDA zone 3 and are herbaceous in nature. For a spectacular evergreen groundcover try the Himalayan Maidenhair (A. venustum) as it features new growth that is tinted bronze and matures around 6” tall.
Adiantum pedatum / Maidenhair Fern, Adiantum venustum / Himalayan Maidenhair
Oak Fern – While we’re on the subject of using ferns as groundcovers I should mention our native Oak Fern or Gymnocarpium dryopteris. With even moisture they form small thickets 6-12” tall through which you can grow other woodlanders such as Solomon’s Seal or Bleeding Heart. ‘Plumosum’ features ruffled leaflets and a fuller appearance.
Hart’s Tongue Fern – Asplenium scolopendrium is a very tropical looking fern with undivided fronds that is actually native to Europe and eastern North America and hardy to USDA zone 5. It actually prefers a neutral to slightly alkaline pH, so add a little lime at planting time if your soil is particularly acidic. ‘Cristatum’ features crested tips, while ‘Kaye’s Laceratum’ looks a lot like leaf lettuce with its intricately divided fronds.
Ostrich Fern – These herbaceous ferns are native to the northern hemisphere and are the source of edible fiddleheads (a key ingredient in my lemon Alfredo fettucine), although they need to be cooked in order to remove natural toxins. They form elegant upright vase-shaped crowns with separate fertile fronds, and spreads by means of rhizomes. Matteuccia struthiopteris ‘The King’ is a larger form (up to 6’) and at USDA zone 3, is very cold hardy.
Autumn Fern – This is the fern I show people who ‘supposedly’ hate them, as the reddish-orange new growth is absolutely spectacular. Dryopteris erythrosora is an evergreen species and even tolerates partial sun with even soil moisture. The cultivar ‘Brilliance’ has the best spring display in my opinion.