Asparagus fern (Asparagus densiflorus), also known as foxtail fern, is a member of the Asparagaceae family. It is a popular houseplant recognizable by its bright green, feathery-textured foliage. Native to South Africa, the warm-weather perennial is closely related to the edible garden asparagus. In zones 9 to 11, these plants are hardy outdoors, growing as creeping spreading plants, but it is also common for them to be grown as indoor houseplants.
Asparagus fern is easy to grow and is normally planted in the spring in warm, humid climates. Indoors, the key to a robust asparagus fern is to keep the plant properly watered, bushy, and dense, so its lace-like foliage forms an attractive mound. It does well in both garden beds and container gardens and pots. When asparagus fern is content in its location, it can produce small flowers followed by berries that are mildly toxic to cats and dogs.
Warning
Asparagus fern can spread rapidly when planted outdoors—to the point of serious invasiveness. Check with your local extension agent to determine if it's invasive in your area.
The Spruce / Leticia Almeida
| Common Name | Asparagus fern, foxtail fern |
| Botanical Name | Asparagus aethiopicus, A. densiflorus |
| Family | Asparagaceae |
| Plant Type | Perennial |
| Mature Size | 3 ft. tall, 4 ft. wide |
| Sun Exposure | Partial |
| Soil Type | Well-drained |
| Soil pH | Acidic, neutral |
| Bloom Time | Spring, summer, fall |
| Flower Color | White |
| Hardiness Zones | 9-11 (USDA) |
| Native Area | South Africa |
| Toxicity | Toxic to humans, toxic to pets |
Asparagus Fern Care
Here are the main requirements for growing asparagus fern:
- Plant in partial shade in organically rich, moist, well-draining soil.
- Grows well in warm, humid climates, but water enough to keep the soil moist.
- Fertilize with a liquid or water-soluble all-purpose plant food.
- Prefers temperatures of a high of 70°F and low of 55°F.
Warning
Asparagus fern is considered an invasive species when planted outdoors in Florida, Texas, and Hawaii.
Light
The asparagus fern thrives in dappled shade, although it can be acclimated to more light. Keep it out of direct, bright sunlight, which may scorch the foliage.
Soil
Plant asparagus ferns in pots or containers in moist, loose, well-drained potting soil. Outdoors, plant it in rich, well-drained soil that is slightly acidic (pH 6.5-6.8). It prefers rich soil to thrive. Make sure containers have drainage holes.
Water
Asparagus fern grows well in humidity, so warmer, humid air and daily misting will help it thrive. Outdoors, keep the plant well-watered and the soil moist to prevent it from completely drying out (You can gauge dryness by the top inch of soil.) Indoor growing conditions are often too dry, especially during the winter heating season. Mist the plant daily, focusing on the arching stems.
Temperature and Humidity
Try to maintain a warm temperature around 70°F and not dip below 55°F for too long. If you have a shady porch or a greenhouse, the indoor plants will likely respond with abundant growth over the summer. Avoid sudden changes in temperatures, which can cause the cladodes to drop.
Fertilizer
Feed asparagus fern with liquid or water-soluble all-purpose plant food diluted to half strength. In the spring, fertilize the plant monthly. During summer, container plants may need weekly feedings; otherwise, feed monthly.
Types of Asparagus Fern
There are several popular cultivars of asparagus fern, including:
- 'Myeri,' which is also known as foxtail fern, has dense foliage on upright stems.
- 'Sprengeri,' which is also referred to as an asparagus emerald fern, boasts long stems and a full, almost fluffy, mounding form.
- 'Sprengeri Compacta' has the same features as its namesake but is a dwarf variety.
- 'Nana' features bright green foliage and is another compact variety of fern.
- 'Foxtail Fern' boasts luscious, fluffy stems of pine needle-like leaves, which gives it a plush appearance and is popular in flower arrangements.
Pruning
Asparagus fern is a fast grower (adding 2 inches of growth per day), so it is crucial to cut at the base of the plant and not in the middle of a stem when pruning. Do not cut more than 1/3 of the plant at a time. Use clean garden shears or sharp scissors to remove brown portions or to regenerate an older plant.
Asparagus fern's “leaves” are leaf-like cladodes. The true leaves are barely visible scales near the base of the cladodes. While the ferns look soft to the touch, they're quite sharp. Wear gardening gloves if you plan to prune an older plant.
Propagating Asparagus Fern
The easiest way to propagate asparagus fern is by digging up and dividing the tuberous roots:
- In spring, dig up the entire plant (or remove it from its pot), using a trowel or shovel. Make sure to wear gloves to protect yourself from the sharp spikes.
- Divide the root clump into sections with a trowel or knife, making sure each section includes a root section, as well as a portion of the crown with growing shoots.
- Replant the pieces into individual pots or their own garden locations. It is best to keep the plant shaded until new growth begins.
How to Grow Asparagus Fern From Seed
Asparagus fern seeds can be found inside the small red berries produced by mature plants. When the berries are fully ripe, mash them and strain out the small seeds. There are typically one to three seeds per berry.
Before planting, scarify and soak seeds overnight. Then, press them on top of the soil. The seeds need light to germinate. Germination should take a few weeks. When true leaves have developed, you can transplant the seedlings into larger pots to continue growing.
Potting and Repotting Asparagus Fern
Plant asparagus ferns in pots or containers in loose, well-drained potting soil. Asparagus ferns grow quickly, and the tuberous roots can easily break a pot. Plan on repotting often. For the most successful repotting, divide the plant into big clumps, and be sure to take multiple underground roots when dividing. Place the divided plants into new pots filled with fresh potting soil. Water well.
Overwintering
If your outdoor temps begin to dip below 55°F, bring your potted asparagus ferns inside. Keep them in bright light, away from drafts and radiators. Make sure to keep soil moist, but do not let the root stand in water, as this can cause root rot.
Common Pests & Plant Diseases
Spider mites, aphids, whiteflies, and mealybugs like to hang out in this plant's leaves; get rid of them with insecticidal soap.
Overly wet conditions can cause root rot. Avoid overwatering to prevent these issues.
Common Problems With Asparagus Fern
While relatively easy to grow, asparagus fern does have a couple of issues that are easily remedied if you know what you're looking for:
Yellow Leaves
Asparagus fern's leaves will turn yellow if the plant has pests—like spider mites or mealybugs—or if your plant isn't getting enough sunlight. This plant's leaves may also turn yellow if it's over-fertilized (the solution is to fertilize less often), or if it has too much or too little light.
Brown Leaves
If your asparagus fern is turning brown and looks like it's drying out, it could be that you have under-watered it. Cut off the brown, dried sections, and try watering more often.
Dropping Leaves
One of the biggest nuisances with asparagus fern is dropping foliage, which can litter floors and tables with fine dried-out needles. This normally happens because of inconsistent watering. While these plants don't like to soak in water, neither do they like to be parched. More frequent watering and misting is usually the solution to a plant that is badly shedding.
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Where is the best place to grow an asparagus fern?
Asparagus fern can be grown both indoors and outdoors. In the house, an east-facing window in a humid environment (kitchen or bathroom) is ideal. Protect it from drafts. If regularly repotted and well cared for, an asparagus fern can have an almost indefinite life as a houseplant. If not regularly divided and repotted, however, it may perish within a few years as it becomes root-bound and overgrown.
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Can asparagus ferns grow outdoors?
Yes, in hardiness zones 9 or warmer, you can grow asparagus fern outdoors as a perennial. Outdoor garden plants have an easier time of it, as they will simply spread to fill available space.
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Is too much sun bad for asparagus ferns?
Yes, too much direct sunlight can be detrimental to asparagus fern, as the plant thrives in partial shade. Too much sun can cause leaf scorch and dry out the plant, preventing it from growing.
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How do you keep asparagus fern plants bushy?
To keep your asparagus fern bushy, make sure it's getting adequate sunlight. If your plant starts to look leggy, you can pinch back some of the stems just at the ends to encourage bushier growth.