Monday, March 9, 2009

Treating Cold-Damaged Palms

By Andy Wilson, Horticulturist

Some areas of Pinellas County, particularly the northeastern section of the county, experienced a night or two of below freezing temperatures this winter. If you have palms showing cold damage, follow these suggestions from the University of Florida to increase the chances that they will recover.

First, remove the cold-damaged portions of the leaves. Leaves that are green but simply spotted from cold damage should not be removed. These leaves are needed to manufacture food for the palm through photosynthesis. Immediately after pruning, spray the palm with a fungicide containing copper at the rate recommended on the label. Add a spreader sticker to the spray solution. After 10 days, repeat the copper fungicide spray or apply another broad spectrum fungicide that is labeled for palms, such as some of the products containing mancozeb or chlorothalonil. After the 2 applications of fungicide have been made, apply a soluble micronutrient spray once a month, continuing into summer. A granular 8-2-12-4 palm fertilizer can applied in the spring and repeated about ever 3 months.

With palms with such severe damage that the spear leaf (the new unopened leaf) pulls out when gently tugged there is still a chance of recovery. Remove as much of the dead and decaying material and possible and then apply the copper fungicide, spraying down into the cavity where the spear leaf was previously attached. Reapply the copper fungicide in 10 days and continue with after care as above.

Remember that full recovery is a slow process. The palm will not look better until it has produced some healthy new fronds.

The information in this article is taken from the fact sheet Treating Cold-Damaged Palms by Dr. Timothy Broschat:

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