Description of Osmunda regalis (Royal Fern)

Osmunda regalis is royal fern, a big UK native fern for reliably damp ground. It’s one of the best plants for giving a bog garden height without flowers. Once it settles, it looks good from spring right through autumn.

Appearance

It makes a large clump of fresh green fronds that can reach well over 1m, and in the right spot it can push taller. In summer, spore-bearing tips turn rusty brown, which gives a slightly different look at the top of the fronds.

In autumn the foliage often takes on bronze tones before it dies back.

Care Guide

Royal fern likes cool, moist soil and it hates drying out.

• Sun: Part shade is ideal. It can take sun if the soil stays cool and wet.
• Soil: Fertile, moisture-holding soil. Neutral to slightly acid suits it well.
• Water: Damp ground is perfect. It can cope near very shallow water, but it’s mainly a bog plant rather than a true aquatic.
• Mulch: A yearly mulch of leaf mould keeps it happy and stops the roots overheating.
• Tidy up: Remove old fronds in late winter before new growth unfurls.

It’s slow to bulk up at first. Don’t move it around. Pick the spot, plant it, then leave it alone.

Suitability for Bog Garden

Osmunda regalis is a top choice for the back of a bog garden or the shady side of a pond. Use it as a backdrop for flowers like Japanese primrose or lobelia, or as a screen to soften a fence.

It also helps with structure. In winter you lose the fronds, but in the growing season it gives a strong, upright shape that stops the bog looking flat.

Space it properly. A mature clump needs room, so don’t cram it tight to smaller marginals.

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