Asparagus Fern
Asparagus setaceus · Lace Fern
It is not a fern at all. It is a flowering plant in the asparagus family, a scrambling evergreen from southern and eastern Africa, and a cousin of the asparagus you eat. Its lacy "leaves" are not leaves either. They are flattened green stems called cladodes.
Family
Asparagaceae
Origin
Southern Africa
In the wild
A scrambling climber
Indoors
0.3–0.9 m
Growth
Moderate to fast
With pets
Toxic
Where it's from
Southern and eastern Africa
African forest margins
Native to South Africa and beyond, on shaded slopes, scrub and forest edges.
Outdoors: zones 9–12
Frost-tender. It dies back in light freezes, so it lives indoors in colder climates.
Invasive where it escapes
A recognised weed in Australia and parts of the warm US. Birds spread its black berries.
A fern that was never a fern
Asparagus setaceus is a flowering plant in the asparagus family, a relative of edible garden asparagus. Those delicate, lacy "leaves" are not leaves at all. They are cladodes, flattened green stems doing the leaves' job. And unlike the Boston fern it copies, this one is toxic.
The leaves are stems
Needle-fine cladodes, flattened modified stems, give it that misty texture.
It flowers and fruits
Small greenish-white flowers give way to berries that ripen black.
Not pet-safe
Steroidal saponins, with the berries the main poisoning risk.
How to keep it
LightBright, indirect
Bright indirect light or filtered sun. Hot direct afternoon sun yellows the foliage.
WaterKeep evenly moist
Water regularly through the growing season. Reduce over winter for a rest.
HumidityLow to moderate is fineUnlike a true fern, it does not demand high humidity. A key difference from the Boston fern.
TemperatureWarm, above 1°CHardy only to about 1°C and intolerant of frost.
SoilWell-drained, peaty mixA well-drained, peaty or soil-based potting mix.
FeedingLight, in growing seasonA light, regular feed through the growing season.
DifficultyEasyTolerates a wide range of conditions and forgives beginners.
With petsToxicSaponins. Skin contact can cause dermatitis, and the berries cause vomiting and stomach upset.
PropagationDivisionSplit the tuberous clump. It also grows from seed. Cuttings do not root well.
RepottingEvery 1–2 yearsOr when the thick tuberous roots crowd and lift out of the pot. Divide at the same time.
What the data says
What it costs
Mass-produced and sold cheaply year-round, including in bulk as a florist filler.
$8–25
Named forms like Nanus and Pyramidalis sit only slightly higher. Nothing approaches collector pricing.
IUCN · Not assessed
In the wild
The opposite of an endangered houseplant. The concern runs the other way.
Common and widespread at home and naturalised well beyond it. Where it has escaped it is a recognised invasive weed, notably in Australia and parts of the warm US, spread by birds eating its black berries. Thriving at home and, problematically, in the wild.
When it sulks
Yellowing, dropping needlesThe number-one complaint. Too much sun, dry soil, or a sudden change. It sheds and leaves bare stems.
Browning tipsUnderwatering, or very dry, hot air.
Leggy, thorny scrambleIt matures into a thorny climber. Prune to keep it bushy and watch the small spines.
PestsSpider mites, aphids, scale and mealybugs.
Varieties & company
The varieties
NanusPyramidalisRobustus
Pairs with · keep apart from
PothosPhilodendronSpider PlantSnake PlantCactiSucculents
A new plant, every week.
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