Beaucarnea recurvata is not a palm. It is related to Agave and Yucca, and the swollen base of its trunk is a water store that gets it through long droughts.
That base is called a caudex, and it explains why this plant tolerates so much neglect.
Light
Beaucarnea recurvata grows best in bright light, including several hours of direct sun. It is one of very few common houseplants that is happier on a sunny windowsill than off it.
Too little light
Growth slows to nothing and the leaves go limp and pale.
Watering
Water thoroughly until it runs from the drainage holes, then wait until the soil is dry throughout before watering again.
On average:
- Spring & summer: every 3-4 weeks
- Autumn & winter: every 6-8 weeks
If you are unsure whether to water, wait. This plant is built for drought and killed by kindness.
Signs of overwatering
- The caudex goes soft or spongy
- Leaves yellow from the base
- Soil stays wet for over a week
Signs of underwatering
- The caudex wrinkles slightly
- Leaf tips go brown and dry
A wrinkled caudex firms up again after watering. A soft one is rotting and usually cannot be saved.
Humidity and temperature
Humidity is irrelevant. Dry indoor air is exactly what it wants.
Keep it between 10°C and 30°C (50-86°F).
Soil and repotting
Soil
A gritty cactus mix with extra perlite or coarse sand. Ordinary compost holds far too much water around the caudex.
Repotting
Every 3 to 4 years at most, into a pot only slightly larger. An oversized pot holds wet soil the roots cannot use, and that is what rots the caudex.
A shallow, wide pot suits it better than a deep one.
Feeding
Cactus fertiliser two or three times over spring and summer. Nothing in winter. It grows slowly and needs very little.
Pruning and grooming
Trim brown leaf tips with scissors, following the natural taper of the leaf, if they bother you.
Do not cut the growing point at the top of the trunk unless you want it to branch. It will not regrow a single head.
Common problems
Soft or spongy trunk base
Rot from overwatering. This is the one serious problem, and it is usually fatal by the time it is obvious.
Brown leaf tips
Very common and cosmetic. Dry air or minerals in tap water.
Yellowing lower leaves
Normal as the plant grows and sheds the oldest leaves. Several at once means overwatering.
No growth
Normal. This plant is genuinely slow, and a few centimetres a year is healthy.