How to Apply Epsom Salts to Palm Trees

Epsom salts (magnesium sulfate) help tackle the symptoms of magnesium deficiency in landscape palm trees like windmill palm (Trachycarpus fortunei), which is hardy in U.S. Department of Agriculture plant hardiness zones 7 through 10. Although magnesium deficiency isn't fatal to palm trees, it causes unsightly, permanent yellow patches on the leaves. Specialized commercial fertilizers like kieserite correct magnesium deficiency in palms, but packets of Epsom salts are easier to find in stores. Another use for Epsom salts is to treat indoor palms. For example, parlor palm (Chamaedorea elegans) is hardy only in USDA zones 10 through 12, so it's often grown as a houseplant. Indoor plants benefit from leaching with a solution of Epsom salts to remove excess fertilizer salts from the potting soil.

Treating Landscape Palms with Epsom Salts

Treat landscape palms with Epsom salts to correct magnesium deficiency or as part of a regular fertilizing program. The major sign of magnesium deficiency in palms is yellow bands along the margins of the oldest leaves, clearly differentiated from the green centers. The leaves never recover, and only fresh new foliage can replace the unsightly leaves. Apply 2 to 4 pounds of Epsom salts per tree four times per year during the growing season to correct the symptoms of magnesium deficiency. Sprinkle the salts evenly over the root zone of the tree and water them into the soil. If the tree is also suffering from potassium deficiency, characterized by brown tips on leaflets, apply controlled-release potassium fertilizer at the same time, following the directions on the product label.

Epsom salts also supply magnesium to palm trees when a regular palm tree fertilizer isn't available. Apply a slow-release 12-4-8 fertilizer to landscape palms every other month during the growing season. On alternate months, apply 2 to 4 pounds of Epsom salts per tree along with a product that contains micro-nutrients for palm trees.

Treating Indoor Palms with Epsom Salts

Epsom salts attach to excess fertilizer salts in houseplant potting soil and help remove them. Signs of fertilizer salt buildup in houseplant potting soil include dried or burned leaf margins and wilting, both of which are due to root damage. To leach fertilizer salts from an indoor palm's potting soil, mix 1 teaspoon of Epsom salts into 1 gallon of water, put the palm container in a sink or bathtub and very slowly pour the solution into the pot. Stop when the water appears through the drainage holes and wait until it's drained away. Pour the Epsom salt solution into the pot three or four times and leave the pot to drain before returning it to its usual position.