By Sara Edelman
Fairchild Tropical Botanic Garden
Palms don't need to be trimmed. Brown leaves protect the center of growth from damage and provide shelter to animals. Sara Edelman Fairchild Tropical Botanic Garden
Palms are the icons of sunny southern Florida. Their beautiful habit and relatively simple growth make them excellent picks for your backyard. However, their horticulture isn't always so straightforward. Many gardeners struggle with trimming, fertilizing, spraying and potting. Here are the answers to some frequently asked questions about palm horticulture.
Q: How should I trim my palm?
A: A good motto for palm trimming is "Don't trim green." Palm leaves store their nutrients in their leaves. A healthy leaf is consistently green. When a palm is nutrient deficient, the leaf starts to change colors. This is caused by the movement of nutrients from their leaves to their growth center. When non-brown leaves are removed, the nutrients in those leaves are removed as well. This essentially starves your palm.
Trimming your palm is not necessary. Some palms, such as royal palms, shed their leaves without any help. Palmetto palms, on the other hand, can hang onto their leaves. Leaving your palm untrimmed may be beneficial to your palm. The old leaves protect the heart (center of growth) from damage during storms. The old leaves also provide habitat to our southern Florida critters.
Before pulling out your clippers or pole saws, remember that palms need their green leaves and are perfectly happy not being trimmed at all.
Q: How do I keep my palm leaves green?
A: Appropriate fertilization is the key to dark green palm leaves. Select an 8-2-12 (N-P-K ratio), slow-release fertilizer. A slow release provides nutrients throughout the year. When spikes in nutrition occur (caused by fast-release fertilizers) palms are left hungry. Feeding palms with fast-release fertilizer is similar to eating all your food for a week on one day. Your palm may be sated for a while but they eventually get hungry and show signs of nutrient deficiency.
Fertilizer should be applied three times a year. The three times fall on a nice holiday schedule: Valentine's Day, Fourth of July and the Jewish New Year (early October). Start thinking about fertilizing on these holidays and you won't miss a fertilizing treatment. These times are perfectly spaced throughout the year so your palms will remain full at all times. No more nutrient deficiencies for your backyard kings.
Q: How do I spray?
A: Spraying is an important part of fertilizing and pest management. The keys to spraying are the same, regardless of the task. Spraying should always be done in the morning. Both liquid fertilizer and horticultural oil will burn leaves if exposed to sun light. Check for morning dew on the leaf and remember the following rhyme: If there is dew, you're safe to spray. If there isn't, try earlier the following day.
Appropriate application is just as essential as timing. Apply the spray evenly over the entire leaf. If the spray isn't even then it won't work. For liquid fertilizer, nutrients have only been delivered to some parts of the leaves and other parts remain deficient. The leaf color will still be distorted. For oil application, only some of the leaf has been treated and the pests will survive and return very quickly.
Q: How do I pot a palm?
A: Most palms are not happy in pots. They can survive a few years in pots but this is not a long-term home for them. It is important to keep them comfortable in their rental unit until you can find them a forever spot in your backyard.
Make sure the roots of the palm are completely covered by soil. Exposed roots are unhappy roots and unhappy roots are fatal. Apply granular fertilizer just below the soil surface and keep your potted palm very well watered. In a potted palm, watering is crucial.
Even though their growth is seemingly simple, appropriate horticulture is vital for the survival of your green giants. Don't struggle with these frequently asked questions. Instead, understand the answers, care for your palms appropriately and watch your collection flourish.
Sara Edelman is the palm and cycad manager at Fairchild Tropical Botanic Garden.