Least Adder's-tongue
Ophioglossum lusitanicum · Ophioglossaceae
The gardener's calendar
Ideal time to plant least adder's-tongue: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Type
- Fern
- Foliage
- Deciduous
- Mature size
- 10 to 20 cm tall
- Growth
- Slow
- Hardiness
- Hardy (down to -10°C)
- Origin
- Mediterranean and temperate regions of Europe
- Soil type
- Well-draining, rich in organic matter
Care
Watering
Keep the soil lightly moist during the growing season (spring-summer), without waterlogging. Reduce watering in winter during dormancy. This fern dislikes both prolonged drought and stagnant water that promotes rot.
Light exposure
Prefer partial shade or dappled light. This delicate fern tolerates intense direct sunlight poorly. A shaded location under trees or near a north-facing wall works perfectly.
Soil and planting
Use a mixture rich in organic matter: potting soil, decomposed fallen leaves, and drainage sand. Portuguese Adder's Tongue appreciates porous, slightly acidic soil. Ensure optimal drainage to prevent waterlogging.
Fertilizing
A light application of balanced fertilizer in spring is more than enough. This fern is not demanding; excess fertilizer could weaken it. Rich mulch (leaves, compost) regularly supplements nutrient content.
Cleaning and maintenance
Regularly remove dried or damaged fronds. No actual pruning is necessary. Gentle cleaning of the leaves with clear water keeps it looking healthy.
Pests and diseases
This fern is generally robust. Watch for slugs and snails, which love tender young fronds. Stagnant excess moisture can encourage fungal rot; ventilate regularly.
Did you know?
Portuguese Adder's Tongue owes its scientific name to the Greek 'ophios' (serpent) and 'glossa' (tongue), as its fruiting structures oddly resemble a serpent's tongue. Remarkably, this tiny fern is one of the rare species of the genus Ophioglossum to be European; most of its tropical cousins display far more spectacular forms.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- MoonwortBotrychium lunaria
- Adder's tongueOphioglossum vulgatum
- Botrypus virginianusBotrypus virginianus
- Leathery grapefernSceptridium multifidum
- Cut-leaved GrapefernSceptridium dissectum
- Lanceleaf grapefernBotrychium lanceolatum
Tips generated and checked by Viridia — adapt them to your local climate.