I learned a trick from our tree guy. Apparently our canary date palm is suffering from lack of acidity causing the leaves to yellow. The secret Loren shared with us -- take a gallon of distilled white vinegar about every two months and pour around the base of the tree. It won't change the leaves already yellowed, but the new growth will remain green. I tried it today and, as my husband and I walked by the tree on our way out, we were reminded of salad dressing. Oh well, it's a refreshing smell and hopefully will help the tree. I'll let you know. Happy Florida Gardening.