The big freeze is behind us now, but the wreckage is becoming more apparent by the day. Many of the city’s iconic palm trees sustained some degree of damage over the winter months. Fronds are brown or browning and, in some cases, dangling precariously over sidewalks and buildings. This creates both an eyesore and a safety hazard.
Here's how to cope with freeze-damaged palm trees.
Sago palms (Cycas revoluta) is not a true palm, but a cycad. Sagos are hardy when it comes to brief periods of freezing weather, and should still be alive and well. Foliage tends to turn brown and die back when temperatures reach the low 20s. These damaged fronds can be cut off anytime — the sooner the better. New fronds will emerge this spring or summer.
Queen palms (Syagrus romanzoffiana) sustained a lot of cold damage and are among the species most likely to have died from the freeze. Queen palms are from climates much hotter than our own and tend to die when exposed to prolonged low temperatures below 25 F. Generally, the more mature the queen palm and the longer it’s been established in the landscape, the better its chance of survival. Buildings and other structures that broke the wind could have also saved some of the queen palms. Trim dead fronds now, and check the “spear leaf” at the top of the crown for signs of life by gently tugging on it. If it pulls right out, the palm may be dead and unable to regenerate. If the spear leaf is still solidly attached, it has a chance of producing new growth. Dan Gill, LSU AgCenter’s consumer horticulture specialist, recommends spraying the spear leaf with copper-based fungicide to protect it from a secondary infection while the palm struggles to recover.
Cabbage or palmetto palms (Sabal palmetto) look rough but in general will recover nicely. Prune dead or discolored fronds and remove lopsided fronds that make the palm appear unbalanced. Palmettos are hardy to 10-15 degrees F, and may be a good choice for replacing dead queen palms in the landscape.
Canary Island date palms (Phoenix canariensis), also known as phoenix palms, are hardy to around 10 degrees. Remove brown or damaged fronds to encourage new growth. If your phoenix palm seems droopy and no healthy spear leaf is apparent, it may be an indication of Lethal Yellowing disease. This disease can mimic cold damage but is always fatal. For more information on Lethal Yellowing please visit lsuagcenter.com.
Lady Palms (Rhapis excela) are sometimes grown in shade gardens in our area. Many of these may have been protected by a wall or building during the cold, and should have been covered to protect them from unsightly cold damage. Lady palms are very low-maintenance and are hardy to 15-20 degrees. Do some selective pruning to remove the fronds that sustained damage. The trunk will produce new foliage this summer.
Windmill palms (Trachycarpus fortune) should have fared well in the freeze, with little to no damage to the fronds. Trim and shape windmill palms now to neaten them up.
Chinese Fan palms (Livistona chinensis), Washingtonia Palm (Washingtonia robusta), and Mediterranean Fan Palm (Chamaerops humilis) should have also fared well and may need some neatening up as well. Other exotic palms may have sustained some cold damage, if you aren't sure what species of palm you have or how to respond to the freeze damage, email the LSU AgCenter at AGCenter@theadvocate.com. To sign up for the GNO Gardening Newsletter, email GNOGardening@agcenter.lsu.edu.
Q: I read on the internet that baking soda mixed with vegetable oil can help control early blight on my tomatoes. I’m planting my early crop now. Is this a good treatment?
A: Anytime an oil is sprayed on leaves there is an increased risk of sun scald and burning. A liquid copper- or sulfur-based fungicide is a better choice for controlling early blight, which is in the soil this time of year.
Trim any leaves that may touch the ground and keep your tomatoes spaced apart to promote good airflow and sun penetration into the plants. Mulch can help prevent soil from splashing on the leaves, which transmits this disease as well.
Water in the morning, using drip irrigation or a hose at the base of the plant. Try to plant your tomatoes in a different spot than before, and remove any diseased leaves quickly to keep the problem from spreading. Don’t compost these leaves, but throw them away. Wash hands and tools after pruning infected leaves to avoid spreading the fungus. Early blight can be managed if caught early and treated accordingly. Spray fungicide so that the leaves are dripping to ensure a good coating.