Overview

Ceterach officinarum is a fern in the genus Ceterach, part of the Aspleniaceae family. Ceterach officinarum grows best in partial shade, and tolerates most soils and alkaline pH. Its UK hardiness is rated H7. Suggested uses include rock gardens, walls and crevices. It is native to Flanders.

About

Ceterach officinarum is a fern in the Aspleniaceae that favours dry, rocky, calcareous locations and is commonly planted in walls and crevices. It prefers partial shade on north or east aspects and tolerates dry to moderate soil moisture. Give it well‑drained alkaline substrate and a sheltered position. In UK conditions it is fully hardy.

Wikipedia contributors, CC BY-SA 4.0 — Asplenium ceterach

About the genus

Asplenium is a genus of about 700 species of ferns, often treated as the only genus in the family Aspleniaceae, though other authors consider Hymenasplenium separate, based on molecular phylogenetic analysis of DNA sequences, a different chromosome count, and structural differences in the rhizomes. The type species for the genus is Asplenium marinum.

In the garden

Ceterach officinarum is a fern of the spleenwort family (Aspleniaceae) native to Flanders and established in rocky, lime-rich habitats. Its ecological niche is on exposed masonry and limestone outcrops, which matches garden situations where drainage is excellent and soil is alkaline. Plants perform best where they can find narrow pockets of mineral substrate rather than deep, moisture-retentive soil. Plant into joints, rock crevices or the gravelly pockets of a rock garden and place where it receives partial shade, especially on north or east-facing aspects. A sheltered position will reduce dessicating winds; avoid exposed sites where moist soils can develop. Use a free-draining, calcareous growing medium and keep soil moisture on the dry to moderate side once established — this species does not suit heavy, waterlogged ground. In the UK it carries an H7 rating, so frost is not usually a problem provided drainage and aspect are correct. Recommended garden uses are walls, rock gardens and crevices where alkaline mortar or limestone provides the substrate it needs. For best results tuck plants into mortar gaps or stony pockets on older limestone walls so they root into the mineral substrate they prefer.

Growing conditions

Best soil and position for Ceterach

Sunlight

Partial shade

Soil type

Well-drained, rocky, calcareous

Soil pH

Alkaline

Soil moisture

Dry to moderate

Aspect

North, East

Exposure

Sheltered

UK hardiness

H7

Plant details

Ceterach officinarum size, habit and characteristics

Plant type

Fern

Suggested uses

Rock gardens, walls, crevices

Native to

Flanders

Care notes

Pruning and caring for Ceterach officinarum

Cultivation

Prefers dry, well-drained soil; avoid waterlogging

Pruning

Remove old fronds in spring

Propagation

Spores, division

Frequently asked questions