Also known as foxtail fern for its upright, fluffy stems, ponytail fern (Asparagus densiflorus "Myers") produces tiny white flowers in summer, followed by bright red berries in autumn. Although ponytail fern has a lacy, fern-like quality, the plant is not a true fern because it grows from seeds and not spores. Ponytail fern, which thrives in full or partial sunlight, grows in U.S. Department of Agriculture plant hardiness zones 9 through 11. In other climates, the plant is grown indoors.
Water outdoor ponytail ferns to a depth of about 6 inches whenever the top 2 to 3 inches of soil is dry. For indoor plants, water slowly until water drips through the drainage hole, then let the pot drain thoroughly. Don't over-water, as the plant prefers soil on the dry side and may rot in wet, soggy soil.
Feed the plant using a dilute solution of a general-purpose, water-soluble fertilizer every week during spring and summer. For indoor plants, mix the solution at a rate of 1/4 teaspoon per gallon of water. Feed outdoor plants at a rate of 1 to 2 teaspoons per gallon of water.
Divide outdoor ponytail ferns every two to three years to keep the plant healthy and vibrant. Use a sharp spade to separate the tubers into smaller sections, then plant the sections in well-drained soil and full or partial sunlight. Similarly, divide an indoor plant or move it into a pot one size larger whenever the plant becomes rootbound enough to raise the top of the soil above the rim of the pot. Fill the pot with any fresh, commercial potting mixture.
Trim the plant as needed in early spring to keep the ponytail fern looking neat and encourage healthy new growth.