Houseplant · Asparagaceae
Foxtail Fern
Asparagus densiflorus 'Myers'
Set it in bright indirect light with a pot that drains, and the foxtail fern raises plumes shaped like green bottle brushes.
Bright indirect
Every 7–10 days
50–77°F · 10–25°C
USDA 9–11
Overview
Almost everyone reads the foxtail fern wrong, and the name is why. The plumes look soft and feathery, yet not a strand of it is truly fern. It sits inside the asparagus family, and rather than shedding spores it opens small white flowers, ripens little red berries, and comes up from seed. On the 'Myers' form the plumes stand stiff and upright, each tapering to a fine point like a plump green bottle brush.
The reason it forgives a careless keeper lies underground. Tucked below the soil are fat tuberous roots that hold their own reserve of water, so a skipped watering barely registers where it would flatten a fussier plant. Give it bright indirect light and a freely draining pot and it asks for little more. Let it run and the clump fills out broad and dense, the plumes arching outward, which is why a stand or a hanging basket shows it off well.
A pair of catches come with it. Every part is mildly toxic to cats and dogs, the bright berries most of all, and the sap can leave bare skin itching. Where frost never bites it slips the garden and naturalizes, so in a warm climate it belongs in a pot and up out of reach rather than turned loose in a bed.
Care
The short version: bright indirect light, a pot that drains freely, and water only once the top few centimeters of soil have dried. Feed it monthly across spring and summer, keep it warm, and split it apart when the tuberous roots begin heaving it up out of the pot.
Light
Set it where bright indirect light falls, close by a window that catches sun without the scorching noon beam landing on it. Partial sun and a touch of shade are tolerated, but starve it of light and the plumes turn thin and pale as new growth stalls.
Water
Reach for the watering can only once the top few centimeters of soil have gone dry, which lands near every 7 to 10 days. Those tuberous roots keep a reserve of their own, so a spell of drying between drinks sits well with it, while soil kept forever wet rots the roots. Pull back through winter as growth idles.
Soil
Root it in a well-draining loamy potting mix that drains through instead of holding a puddle. Aim for a pH between 6.0 and 7.0, close to neutral, and it stays content. Free drainage counts above everything else, because waterlogged roots are the quickest way to lose it.
Temperature
Everyday indoor warmth of 50°F to 77°F (10°C to 25°C) hits the mark. Frost will finish it, so keep it clear of cold windowsills and the chilly drafts that creep in through winter.
Humidity
It fares best in moderate humidity of about 40% to 60%, though it takes no offense and handles ordinary indoor air. Should the plume tips brown in a dry, heated room, lift the moisture in the air nearby.
Feeding
Offer a balanced water-soluble fertilizer monthly from spring through summer while it is putting on growth. Hold off across the cold stretch when it rests, and rinse the pot through occasionally so feeding salts never build to a crust.
Pruning
Snip spent or yellowed plumes off flush at the base to hold the clump neat and draw out fresh upright growth. Worn or damaged stems take a hard cut in spring to renew the plant. Slip on gloves first, since the sap can nettle the skin.
Repotting
Move it up every 2 to 3 years, or earlier the moment the swollen tuberous roots start shoving it clear of the pot. Roots circling the container and water sluicing straight through without soaking in are the other giveaways. Spring is the season for it, often paired with splitting the clump.
Size & spacing
Grown indoors it climbs to 24 to 35 inches (60 to 90 cm) and fans out broader yet, 3 to 4 feet (90 to 120 cm) across. Leave the clump space for its plumes to arch clear, which is why a stand or a hanging basket fits it.
Troubleshooting
Long before the plant as a whole falters, the foxtail fern says its piece through the plumes. Yellowing, dropping needles, and browned tips each trace back to their own cause. Find the match below and correct it before the trouble widens.
Yellow creeping through every plume on the plant
When the green drains out of plume after plume, soggy soil at the roots is the first thing to suspect, since the fleshy tubers sour in standing wet. A dim corner or an empty feeding schedule will yellow them too. Let the top few centimeters go dry underfoot before the next drink, shift the pot toward brighter light, and pick the monthly feed back up as it grows.
Fix:
- Allow the top few centimeters of soil to dry before watering
- Move to a brighter spot with bright indirect light
- Resume monthly feeding during the growing season
Fine needle foliage raining down onto the floor
The slim green cladodes are the first thing a thirsty plant lets go of, scattering across the floor when the root ball has run bone dry. A cold draft or an abrupt new spot pushes the same shed. Soak it through and hold to an even watering rhythm. Park it out of drafts and clear of heat vents under steady bright indirect light, and the needle drop tapers off.
Fix:
- Water thoroughly and maintain a consistent moisture cycle
- Keep the plant away from cold drafts and heat sources
- Provide steady bright indirect light
Crisp brown ends drying out the plume tips
Parched air scorches the fine tips first, turning the plume ends brown and brittle, and both a bone-dry root ball and a crust of feeding salt push them the same way. Lift the moisture in the air around the foliage and hold the soil evenly damp while it grows. Now and then, run plain water through the pot to rinse out the salts that gather from the fertilizer.
Fix:
- Raise humidity around the plant
- Keep soil evenly moist during active growth
- Flush the soil periodically to leach excess salts
Toxicity
Keep this one well beyond reach of pets. The sap and those glossy red berries are where the danger sits, filed by the ASPCA under Asparagus Fern as toxic to cats and dogs, and the same sapogenins mean horses, rabbits, and grazing stock ought to stay clear too. People are meant to eat none of it, the berries turn mildly poisonous, and the sap can flare up a rash, so pull on gloves before you prune.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Moderate
The ASPCA flags the sapogenins in this plant as toxic to cats. Bite into the glossy red berries and a cat tends to vomit, ache in the belly, and pass loose stools; rub against the cut foliage over and over and the skin can turn red and sore.
Dogs Moderate
A dog fares no differently. The berries bring on vomiting, diarrhea, and belly pain once chewed, and repeated brushing against the cut stems can raise an itchy, inflamed patch of skin.
Horses Caution
No horse-specific case sits on record, yet the same sapogenins that turn a pet's stomach mark this out as one to keep clear of horses. Don't let one crop the foliage or nose at the fallen berries.
Rabbits Caution
Count it as forbidden for rabbits. Both the berries and the sapogenin-laced tissue can upset a gut, so set the pot and every dropped fruit far past their reach.
Livestock Caution
Goats, sheep, and cattle meet the same toxin the moment they reach the foliage or the ripe red berries. Fence it off, or place it somewhere grazing animals simply cannot get at it.
Birds Caution
Out in the wild, birds swallow the berries unharmed and carry the seeds off, which is exactly how it slips into open country, but a curious pet bird has no business pecking the fruit. Keep it clear of cage birds to stay on the safe side.
People Caution
None of this plant is meant for the plate, and the red berries turn mildly poisonous if swallowed, so keep children away from them. Bare hands on the stems and sap can leave a rash behind, which is why gloves go on before any pruning or repotting.
Wear gloves when pruning or repotting, as repeated skin contact with the sap can cause allergic dermatitis.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Two forms of Asparagus densiflorus travel under the asparagus fern name, and their growth could hardly differ more. Sorting out which you hold tells you at once whether it climbs upright or spills down.
Asparagus densiflorus 'Myers'
Here is the genuine foxtail, its plumes standing packed and upright, each one tapering to a fine point in the exact shape of a bottle brush.
Asparagus densiflorus 'Sprengeri'
The common asparagus fern instead cascades in loose, arching, trailing stems, nothing like the rigid vertical plumes that mark out 'Myers'.
How to propagate
More foxtail ferns come the fast way by splitting a clump apart, or the patient way by sowing the seed drawn from its berries.
DivisionEasy
Spring or early summer at repotting · 4 to 8 weeks
Splitting the plant is the simplest route to more, and it slots right into a spring or early summer repot. Ease the root ball out and cut the thick tuberous mass into pieces, checking that every one holds both green stems and living roots. Set the pieces into their own pots and they take hold across the following 4 to 8 weeks.
SeedModerate
Spring · Several weeks to germinate, months to reach size
Seed is the slower, more testing path. Come spring, gloves on against the skin-irritating fruit, work the seed loose from the ripe red berries and press it into a warm, damp mix. Sprouting drags on for several weeks and comes up patchy, and it takes months beyond that before the young plants gain any real bulk.
Myths
The foxtail fern is a true fern.
The name leads you astray. It is no fern whatsoever, belonging instead to the asparagus family, Asparagaceae. True ferns scatter spores to reproduce; this one puts out flowers, ripens red berries, and starts life from seed.
Because it's a fern, it must be safe around pets.
Neither part of that holds. Under Asparagus Fern the ASPCA marks it toxic to cats and dogs, the berries souring the stomach and the sap raising an itchy rash. Keep it well out of range of anything that likes to chew.