Triangle palms add that tropical feel to the landscape. The triangle palm grows its fan-like fronds from three points on the trunk, making a triangle. This palm is single-stemmed and will grow to 25 feet tall. Slow-growing with blue/green foliage, the triangle palm is hardy from USDA planting zones 9b through 11. The tree can be grown from seed and the seeds are poisonous if eaten.
Water the tree for long periods once a week when young and every other week for older trees. Spread the water in a 3- to 6-foot diameter of the trunk, as the root system spreads far. Cut watering back to once a month in early winter to prevent the tree from freeze damage.
Apply a palm tree food in April, June and August. Follow manufacturer's directions on how much to apply for the size and age of the tree.
Cut off palm fronds that are yellowing or dead as close to the stem as possible, using a ladder and long-handled pruners. Do not prune the triangle palm as the fronds gather nutrition for the tree and cutting them off will leave the tree weak.
Apply an extra dose of fertilizer if the tree develops yellowing in the crown, yellowing or bleaching to the fronds or spots on the fronds that just do not look normal. These are signs of a nutritional deficiency, usually caused by using a general-purpose fertilizer not made especially for palms.