Ferns🌿 Native to the NetherlandsVery hardy — tolerates frost down to -20°C

Intermediate polypody

Polypodium interjectum

From€6.45incl. VAT

Select a size to order

Choose a size

Intermediate Polypody (Polypodium interjectum) is an evergreen fern with broad, leathery fronds growing from a creeping rhizome. The species strongly resembles the common polypody and can sometimes only be reliably identified by its ripe spores and sori. The fern grows in warm, stony, and well-drained places, including old walls, rocks, calcareous dunes, dikes, and tree bases. It tolerates some drought but requires sufficient moisture during establishment.

Specific care needed

Plant in a stony, airy, and strongly draining substrate. Do not bury the creeping rhizome deep. Keep the plant sufficiently moist during the first growing seasons and avoid heavy fertilization.

Year calendar

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec

Pruning period

✂️Best pruning period: Feb–Mar

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
✂️ Pruning period

Best pruning period

Remove only damaged or completely dead fronds.

Botanical profile

Site & soil

Sun, Half shade

Soil type: Sand, Loam, Humus-rich

Moisture need: Dry, Moderately moist

pH: Slightly acidic (5.5–6.5), Neutral (6.5–7.5), Chalky (>7.5)

Nutrient richness: Very nutrient-poor, Nutrient-poor

Humus content: Humus-poor, Moderately humus-rich

Water drainage: Strongly draining, Well draining

Appearance & season

Mature height: 10-45cm

Bloom: Niet van toepassing

Autumn colour: Evergreen.

Properties

Salt sensitive: Yes

Edible: No

Historical use of polypody roots makes this species unsuitable for consumption.

Scent: No striking scent. The rhizome and bruised foliage can smell slightly earthy.

Creeping rhizome: Yes

This fern has a creeping rhizome that can spread underground — give it room or keep it in check with a root barrier.

Ecological value

The evergreen fronds are used by specialized fern caterpillars, leaf miners, and other small insects. Spiders, springtails, beetles, and snails live among the creeping rhizomes. The mat retains thin layers of humus and fine organic material on stones and slopes. Birds can search for small invertebrates among the fronds. The plant offers micro-shelter throughout the year but is of limited significance to mammals due to its low growth.

Food web & Biodiversity

🐛 Caterpillars & mothsVery useful

🐝 Bees & bumblebeesLimited

🪰 HoverfliesUseful

🦋 ButterfliesUseful

🪲 Beetles & insectsVery useful

🐦 BirdsUseful

🐿️ MammalsUseful

🐞 Other animalsUseful

Intermediate polypody is particularly important for small animals that live directly on fern leaves or in stony microhabitats. The evergreen mat remains available as shelter outside the growing season. For pollinators and larger mammals, its direct value is minor.

Distribution in the Netherlands