Yucca plant care indoors

Yucca plant care indoors comes down to more light and less water than most houseplants get: put it in the sunniest window you have, water deeply only when the top 2 inches of soil are dry, and cut back sharply in winter. A healthy yucca cane is hard as wood at the soil line; a soft or wobbly cane means rot. The ASPCA lists yucca as toxic to dogs and cats.

What indoor yucca is

The yucca sold as a houseplant is almost always the spineless yucca, Yucca gigantea (long sold as Y. elephantipes), a Central American species from the agave subfamily, related to dracaenas and snake plants. Unlike the stiff garden yuccas, its leaves lack a sharp spine at the tip. The RHS describes Y. elephantipes as a tender, upright shrub or small tree with several trunks that can reach 30 feet in the wild and is ideal as a houseplant.

Look-alikes: ponytail palm has a swollen base and thin curling leaves; dracaena and corn plant canes have softer, broader leaves and prefer much less light.

Light: how much it really needs

Yucca is the one "easy" houseplant that does not tolerate shade. The RHS says yucca requires a sunny position all year: a south-facing window is ideal in winter, an east- or west-facing one in summer, with light shade from direct summer sun and good ventilation to avoid overheating.

Signs of low light: new leaves longer, narrower and paler than the old ones, flopping instead of standing. Stretched leaves won't shorten; only new growth improves. In winter, a strong grow light helps; see grow lights. Rotate the pot regularly, as the RHS advises, so it doesn't grow lopsided.

Watering by pot size and temperature

In partial shade, stretch the intervals by half again.

How to check: a wooden skewer pushed 2-3 inches in comes out dry, and the top layer isn't cool to the touch. In a big tub, go by that depth, not the bottom of the pot. Clemson Extension calls overwatering the leading cause of potted-plant death, recommends watering until water runs out the bottom to flush salts, emptying the saucer, and using water at 62-72°F. Avoid softened water, which adds sodium.

Why water even less in a cool room: at 50-60°F a yucca nearly stops growing and uses almost no water, while a big tub dries three to four times slower than in summer sun. Wet, cold soil is exactly the condition that rots the cane. More in our watering guide.

How to check the cane for rot

Check when you see many soft yellow lower leaves, the plant rocks in the pot, the soil smells sour, or there's a dark wet patch on the bark.

1. Squeeze the cane right at the soil line. Healthy tissue is hard like wood.
2. Work upward in 4-inch steps; the first soft spot marks how far the rot has gone.
3. Test the bark with a fingernail: if it peels in strips over brown mush, that tissue is dead.
4. Rock the plant gently. A cane that moves freely in the soil has lost its roots.
5. If in doubt, unpot: live roots are pale and firm; rotted ones are dark, slimy and the outer layer slips off.

Normal vs. problem: 1-2 yellow lower leaves a month with a firm cane and a dense green crown is just growth; the RHS notes some yellowing of lower leaves is normal. Dozens of soft yellow leaves in a couple of weeks is not.

Rescuing an overwatered yucca

1. Unpot right away and rinse the roots with lukewarm water.
2. With a clean knife, cut off all dark, slimy roots back to firm, pale tissue.
3. Check the cane from the bottom. If it's firm, replant. If the base is soft but higher up is firm, saw it off 2-4 inches above the rot, into clean white wood.
4. Let the cut dry in the shade for several days.
5. Plant the living part in dry, gritty mix in a pot 1 inch wider than the roots.
6. Wait 10-14 days before watering, then water sparingly.
7. Keep it at 68-77°F in bright light out of direct sun, with no fertilizer for two months.

If roots survived, new leaves usually appear in 3-8 weeks. See root rot and overwatering.

Temperature and humidity

Yucca likes 60-80°F in the growing season. The RHS notes Y. elephantipes tolerates a winter night minimum of 45°F (7°C) when not actively growing, with days a few degrees warmer, and lists 50°F (10°C) as its minimum as a houseplant. A cool, bright winter room is ideal, as long as the soil stays on the dry side. Dry indoor air doesn't bother it; keep it away from blasting heat vents, which encourage spider mites.

Soil, pot and repotting

Use a gritty, fast-draining mix: cactus and succulent mix, or indoor potting mix with about 30% perlite or coarse grit. Choose a heavy terracotta or ceramic pot with drainage: tall yuccas are top-heavy. Repot in spring every 2-3 years, only 1-2 inches larger, keeping the cane at the same depth. Large plants can stay put with a top-dressing of fresh mix each spring. See repotting and potting soil.

Feed lightly from April to September with a balanced liquid houseplant fertilizer at half strength once a month; none in winter. More in fertilizer.

Cutting back a tall yucca

The RHS says pruning isn't normally needed, but if the plant gets too tall you can cut it back, reducing its height by half.

1. Prune in spring when growth starts.
2. Saw through the cane cleanly at the height you want.
3. The stump sprouts 1-3 new rosettes just below the cut within weeks to a couple of months.
4. Keep the stump on the dry side until new leaves appear; it has fewer leaves to use water.
5. Remove dead lower leaves by pulling down sharply or cutting close to the cane.

Propagating from the top

The RHS recommends spring stem cuttings 8-10 inches long, measured from the tip, in coarse sandy rooting mix.

1. Strip the lowest leaves from the cutting and let the cut end dry for a day or two.
2. Insert 2-3 inches deep in gritty mix.
3. Keep in bright, indirect light at 70-77°F; water lightly when the mix dries.
4. Roots typically form in 3-6 weeks; new leaves in the center show it has taken.

Offsets (pups) that appear at the base can be separated with some roots in spring. More in propagation.

Summering outdoors

The RHS suggests tender yuccas can go outside from late May to August in a sheltered spot, as long as the pot won't blow over. In US terms: once nights stay above 50°F, start in bright shade and add direct sun over 1-2 weeks to avoid sunburn. Bring it in before frost.

After you buy a yucca

Yucca canes are cut trunk sections that were rooted at the nursery, often in a tight pot of peat-heavy mix that holds water far longer than a yucca likes. The first month decides a lot.

1. Squeeze every cane at the soil line; all should be rock hard. Return or replace a plant with a soft cane.
2. Check whether the canes rock in the pot: a little movement is common in young canes, a lot means few roots.
3. Remove decorative sleeves and set it on a saucer you can empty, never in a cachepot that hides standing water.
4. Place it in the sunniest window right away, but shield it from hot afternoon sun for the first two weeks.
5. Don't water until the top 2 inches are dry, even if the leaves look dusty or tired.
6. Repot into gritty mix the following spring, not immediately.

Losing a few lower leaves in the first weeks is normal as it adjusts from greenhouse light.

Pests

Indoors, watch for spider mites in warm, dry rooms and scale along leaf bases. Rinse or wipe the leaves, scrape scale off with rubbing alcohol on a swab, and use a labeled houseplant insecticide or miticide only for heavy infestations.

Toxicity

The ASPCA lists yucca (Yucca spp.) as toxic to dogs and cats, with vomiting as the clinical sign (in horses: liver disease and dermatitis). If a pet chews it, call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435; for a child, call Poison Control at 1-800-222-1222. See toxic plants.