Spineless yucca care guide

The spineless yucca grows tufts of long, sword-shaped leaves on top of thick, woody canes. It is the yucca sold as a houseplant. The name means its leaves end in a soft point, not the sharp spine of outdoor yuccas. It loves sun, handles dry air, and does not mind a missed watering.

Light

Give it the brightest spot you have. A south or west window is best. It can take direct sun.

In low light, new leaves grow thin, pale, and floppy. It leans toward the window. Turn the pot every few weeks.

It can spend summer outside. Start it in shade for a week, then move it into more sun over another week. Bring it in before nights drop below 10°C (50°F).

Water

Water when the top half of the soil is dry. Water until it drains, then empty the saucer. In summer, that is about every two to three weeks. In winter, once a month is often enough.

Too much water is the most common way to kill a yucca. The cane rots from the base. Read how to tell if a houseplant is overwatered or underwatered.

Soil and potting

Use a cactus mix, or a houseplant mix with extra perlite or grit.

Tall yuccas get top-heavy. Use a heavy clay or ceramic pot. Repot every two to three years in spring, one size up. See how to repot a houseplant step by step.

Humidity and temperature

Dry indoor air is fine. Keep it between 16 and 29°C (60 and 85°F). It handles cool rooms down to about 7°C (45°F).

Feeding

Feed two or three times in spring and summer with a balanced liquid fertilizer at half strength. Skip feeding in fall and winter.

Pruning

Lower leaves turn yellow, then brown, as the plant grows. Pull them down and off, or cut them close to the cane.

If a cane gets too tall, cut it in spring. Use a clean saw or sharp knife. Cut at any height. Two or more new tufts of leaves sprout just below the cut in a few weeks. Keep the top to grow a new plant.

Propagation

Cut the top off a cane with a tuft of leaves. Let the cut end dry for a few days. Set it in a pot of damp cactus mix. Keep it in bright light and water it a little when the soil dries. Roots take four to eight weeks.

Older plants also grow pups at the base. Cut a pup away with some roots attached and pot it on its own.

Problems

What you see	Most likely cause
Brown leaf tips	Dry soil, or salts in tap water
Lower leaves turn yellow and brown	Normal aging, or too much water
Soft, mushy cane	Root rot from too much water
Thin, pale, floppy new leaves	Not enough light
Brown spots on leaves	Leaf spot from water sitting on leaves
Fine webbing under leaves	Spider mites

Pests

Spider mites, scale, and mealybugs are the most common pests. Check under the leaves and where they join the cane. Wipe the leaves with a damp cloth every few weeks.

Pet safety

The ASPCA lists yucca as toxic to cats and dogs. It contains saponins that can cause vomiting and diarrhea.

Varieties

• Green spineless yucca, Yucca gigantea, has plain green leaves. It is the most common.
• Yucca gigantea ‘Jewel’ has cream and green striped leaves.
• Yucca gigantea ‘Silver Star’ has narrow leaves with white edges.

This yucca does not survive frost. Outdoor yuccas that grow in cold climates are different species.