A ponytail palm (Beaucarnea recurvata), also known as bottle palm, nolinas and elephant-foot tree, is a type of succulent that grows up to 30 feet tall outdoors. It grows outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 12 or you can grow it as a houseplant. A ponytail palm does not need to be watered as often as many other houseplants. Overwatering can quickly kill this drought-tolerant plant. Take steps to remedy the problem at the first signs of overwatering.
How a Ponytail Palm Uses Water
A ponytail palm absorbs water through its roots then stores the water in its trunk. If it is watered too frequently, the roots cannot absorb the excess water and the soil stays wet. The roots are deprived of oxygen and essentially drown. The roots become mushy and unable to absorb more water when the plant needs it.
Signs of Overwatering
Brown leaf tips are an early sign of over-watering. If overwatering continues, the leaves will wilt, new leaves will be smaller and the ponytail palm could be stunted. The leaves will turn yellow and drop. Eventually, the whole tree wilts.
As soon as you see brown leaf tips, allow the soil to dry out before watering a ponytail palm again. Trim the brown leaf tips off with a pair of sharp scissors. Let the soil become almost completely dry before giving a ponytail palm more water. Always empty the catch basin beneath the container of a container-grown ponytail palm after the water drains through. It will leach back up into the potting soil and keep it wet. When more advanced signs of overwatering show up, the ponytail palm may have developed root rot, a fungal disease that flourishes in wet soil.
Saving a Container-Grown Ponytail Palm
A container-grown ponytail palm with advanced signs of overwatering should be repotted right away. Tip the container on its side and slide the ponytail palm out. Brush or gently shake the potting medium off the roots to examine them. If more than one-half the roots are gray or brown and mushy, the plant cannot be saved. If most of the roots are still white and firm, repot the ponytail palm. Use sharp, sterilized scissors to trim off the infected roots. Sterilize the scissors by spraying them with household spray disinfectant. Rinse the disinfectant off the scissors before using them. Disinfectant damages plant tissue.
Use cactus mix potting soil. Use a new container with at least one drain hole in the bottom so excess water will drain away. Clay or terra cotta containers are best. They are more porous and provide better air circulation.
Saving an Outdoor Ponytail Palm
An outdoor ponytail palm with advanced signs of overwatering and possible root rot will be difficult to save. Pull the soil back away from the base of the tree to expose the top roots and flare at the base of the trunk. Do this carefully with a small shovel or by hand. Do not injure the trunk. The base of the trunk may be darkened from the excess moisture. Allow the soil to dry completely before watering it again. If the ponytail palm does not begin to recover quickly, it will likely have to be removed. When the roots are rotten, there is nothing to hold the tree upright. This can be a safety hazard if the tree is large.