Why Hart's Tongue Fern Earns Its Place in Shade

Hart's tongue fern, Asplenium scolopendrium, is one of the most dependable evergreen ferns you can grow in a British garden. Its fronds are undivided, strap-shaped and glossy, with a leathery texture that shrugs off winter cold and holds its colour right through to spring. In the wild you will find it in damp shady lanes, on old walls, in churchyards and along limestone banks, which tells you almost everything about what it wants: cool shade, steady moisture and soil that leans alkaline.

That last point matters. Most ferns demand acid, leafy ground, so gardeners on chalk or limestone often feel left out. Hart's tongue is the happy exception. Give it a cool corner and it will settle for decades, slowly building into a substantial clump that looks good in every month of the year.

Choosing the Right Spot in the Border

Aim for a north or east-facing border, or the dappled shade beneath deciduous trees and shrubs. Deep shade is fine; a little early morning sun is fine too. What it cannot take is hot afternoon sun and drying wind, which scorch the fronds to papery brown within a week or two.

Check the soil before you commit. Hart's tongue likes moisture that drains away freely — it sulks in winter waterlogging, and it will not thrive in thin, parched ground under greedy tree roots unless you improve it first. If your soil is naturally acid, do not despair: plant into a raised bed or a large pot using a loam-based compost with a handful of horticultural lime or crushed limestone mixed through.

Preparing the Ground Before Planting

Bare-root ferns establish far better in ground that has been opened up properly, so spend twenty minutes on preparation for every plant.

• Clear perennial weeds thoroughly — couch, ground elder and bindweed will outcompete a young fern.
• Fork over the top 20–25cm, breaking up any pans or compacted layers.
• Work in two or three generous handfuls of leafmould or well-rotted garden compost per square metre.
• If your soil is acid, add horticultural lime at the rate on the packet, or incorporate crushed limestone grit.
• Water the prepared area the day before planting if the ground is dry.

Settling Bare-Root Plants Step by Step

Bare-root hart's tongue is usually lifted and sold during autumn and winter dormancy, which is exactly when it transplants best. Unpack it the day it arrives.

• Soak the roots in a bucket of water for twenty to thirty minutes before planting. Trim any broken or shrivelled roots back to clean tissue.
• Dig a hole wide enough to spread the roots out flat, and no deeper than the roots are long.
• Form a cone of soil in the base of the hole and drape the roots over it, spreading them evenly.
• Set the crown — the point where the fronds emerge — level with, or just a whisker below, the soil surface. Bury it and the plant will rot.
• Backfill and firm gently with your knuckles, working soil in among the roots without compacting it hard.
• Water thoroughly with a full watering can, then water again the following day.

Space plants 30–45cm apart. They look sparse at first, but hart's tongue fills out steadily and a tight planting only invites crown rot.

Watering, Mulching and the First Season

Newly planted ferns need help through their first spring and summer. Keep the ground evenly moist — never sodden — and water in the morning during warm spells so the foliage dries before evening. A mulch of leafmould or garden compost, spread 5cm deep but kept clear of the crown, will hold moisture and feed the soil gently. Avoid rich fertilisers; too much nitrogen produces soft fronds that scorch and flop.

Slugs and snails will nibble young croziers in spring, so set a few traps or patrol after rain. Frost is rarely a problem, but newly planted ferns can be lifted by heaving, so check them after a hard spell and firm them back in. Remove tatty old fronds in late winter, before the new ones unfurl, and leave the rest untouched.

Companions and Long-Term Care

Hart's tongue combines beautifully with hellebores, epimedium, pulmonaria, wood anemone, snowdrops and cyclamen, all of which enjoy the same cool, limey conditions. Let it seed into wall crevices, where its roots will find the mortar it loves. After several years, lift and divide congested clumps in early spring, replanting the outer portions and discarding the woody centre. Do that every few seasons and a single plant will reward you with a colony of glossy green for a generation.