With their large, dramatic leaves, palms provide a tropical accent to indoor or outdoor gardens. Some varieties, such as the parlour palm, have feather-shaped leaves; others, such as the lady palm, have fan-shaped leaves. Palms thrive in sunny tropical or subtropical climates, but will grow indoors in colder climates. Cold temperatures, as well as improper fertilisation, watering, and pruning, can cause brown tips to develop on the leaves.
Over-fertilisation, as well as magnesium and potassium deficiency, can cause lower leaf tips to turn brown. According to the University of Florida Escambia County Extension, a palm fertiliser should contain nitrogen, phosphorus, potassium and magnesium in an 8-2-12-4 proportion. Garden supply centres sell fertilisers specifically prepared for palms. Container-grown plants are more susceptible to damage from excessive fertilisation; use a slow-release or diluted liquid fertiliser for a container-grown palm. To avoid build-up of fertiliser salts, use well-drained soil and water thoroughly before the soil completely dries out.
Palms grow best in well-drained, moist soil; brown leaf tips can develop in dry conditions. During the spring and summer, water thoroughly as soon as the soil surface feels dry, but do not allow the soil to become waterlogged. After you water your palm, empty the excess water from the drainage saucer. During the winter months, you can water less frequently. Clemson University Cooperative Extension recommends regularly spraying a palm with lukewarm water to remove dust and insects.
Cold temperatures can injure palm leaves. When the temperature falls below 7 degrees C (45 degrees F), brown areas can develop on the leaves. During the spring and summer, keep daytime temperatures between 21.1 and 26.6 degrees C (70 and 80 degrees F); nighttime temperatures should not fall below 15.6 degrees C (60 degrees F). During the winter months, a palm will tolerate temperatures between 12.7 and 15.5 degrees C (55 and 60 degrees F). The University of Florida Escambia County Extension recommends hardy varieties, such as pindo palm, for cooler regions. Keep indoor palms away from drafts or air conditioning vents.
You may be tempted to remove all browned leaves; however, excessive pruning can cause further damage to your plant. To compensate for nutrient deficiencies, older leaves send nutrients such as potassium and magnesium to the younger leaves. Excessive pruning can lead to greater nutrient deficiencies and more browned leaves. According to the Florida Hernando County Extension Service, you should never remove more than one-third of the leaves from a palm.
- University of Florida Escambia County Extension; Palm Care; 2006
- Clemson University Extension Service; Indoor Palms; Karen Russ; April 1999
- Florida Hernando County Extension Service; Death by Pruning; Jim Moll; July 2002
- University of Minnesota Extension Service; Grow Palms Indoors; Deborah L. Brown; October 1998