Asparagus Fern
Not a fern at all but a relative of edible asparagus, with feathery, needle-like foliage cascading from a pot on wiry stems. Much tougher than a real fern: it stores water in tuberous roots and tolerates dry air. Toxic to pets if the berries are eaten.
The asparagus fern is a lie in two words. It is not a fern, and the "needles" are not leaves but flattened stems; it is a cousin of the asparagus you eat, from South Africa, and it behaves like a drought-adapted plant rather than a rainforest one. Wiry, slightly thorny stems arch out of the pot carrying clouds of fine green needles, and a big plant in a hanging basket is a soft green fountain.
Underground it has fat water-storing tubers, which is why it survives neglect that would kill a real fern. It tolerates dry air, bright light and a missed watering. It does drop needles when unhappy, and it does grow small red berries that are toxic to pets.
Light
Bright, indirect light with some direct morning sun keeps it dense and green. It takes more light than a true fern and goes sparse and yellow in a dim corner. A few feet from a south or west window is fine; hot midday sun through glass yellows the needles.
Water
Water when the top inch is dry, weekly or so in summer and every ten days in winter. The tubers hold water, so it forgives a missed week. Left dry too long it sheds needles in a shower; overwatered, the stems yellow from the base. Drain well.
Soil and potting
A well-draining potting mix with a third perlite. Pot with drainage. The tubers fill a pot fast and can crack plastic, so repot every eighteen months, two inches up, and trim the tubers if they have taken over.
Feeding
Half-strength balanced feed every four weeks in spring and summer. It is a fast grower and uses it; underfed plants go pale.
Propagation
Division in spring is easiest: cut the tuberous clump into sections with stems and pot up. Seed from the berries also germinates readily.
In a hot, dry home
Very good in a dry home. It comes from dry South African scrub, stores water in its tubers and tolerates heat and low humidity. Give it the bright spot a real fern could not take, water when the top inch dries, and keep it out of the direct AC stream, which makes it shed. It is the fern-look for a house that cannot keep ferns.
Asparagus Fern varieties
Same care, different look. These are the named forms you will see for sale.
- Sprengeri
The trailing form with long, arching stems. The usual hanging-basket plant.
- Myers (Foxtail)
Dense, upright, bottle-brush plumes instead of trailing stems. Slower.
- Plumosus (Lace fern)
Asparagus setaceus: flat, feathery, almost horizontal sprays. Climbs given the chance; wants a little more humidity.
Problems and fixes
Needles dropping in showers
Likely cause: Dried out too far, or moved
Fix: Water thoroughly and keep it steady; it regrows.
Yellow, sparse stems
Likely cause: Not enough light or underfed
Fix: Brighter spot; feed monthly.
Stems yellow from the base, soggy soil
Likely cause: Overwatering
Fix: Let the top inch dry; check drainage.
Roots pushing out of the pot
Likely cause: Tubers filling the pot
Fix: Repot, trimming some tubers.
Asparagus Fern questions
Is asparagus fern safe for cats and dogs?
No. The berries cause vomiting if eaten and the foliage can irritate skin. Hang it out of reach.
Is it a real fern?
No. It is a relative of edible asparagus and grows from water-storing tubers, which is why it is far tougher than a true fern.
Why does it drop needles?
Drought, a sudden move, or a cold draft. It sheds and regrows. Keep the watering steady and it stops.
Plants with a similar rhythm
Boston Fern
- Light
- Medium to bright indirect
- Water
- Every few days
- Pets
- Safe
String of Pearls
- Light
- Bright indirect to direct sun
- Water
- Every 2 weeks
- Pets
- Toxic
