Palm Trunk Loss of Wood Growing in Lawns

Q. I live in a cold climate area in Australia. Palms are unfortunately rare in a garden in our area. But in our local park we have two big old palms. I have noticed the bases on them look a bit odd. Is this normal? Sorry, I don’t know what type it is. I have attached photos.

On trees growing with overhead irrigation typically have loss of one from their trunks at the base. This is from irrigation water constantly hitting them.

A. Usually that type of deformity (wearing of the “wood”) of palm tree trunks is caused by the irrigation sprinklers constantly hitting it. Palm trees are monocots and so their distribution of water through the trunk is different than for many other trees. Most trees rely on renewal of the water conducting tissue from a “ring” of growth (cambium) that grows just beneath the bark.

Palm trunk starting to get grotesque

            Nothing to worry about in palms. With lawn overhead irrigation, that is considered "normal" for palms. By the way, most palm trees should not be grown where there are lawns (we call these types of landscapes, “mixed landscapes”) but irrigated separately. Tree and shrub irrigation is different from lawns and they interfere with any overhead irrigation supplied to lawns.

Cross-section of a dicot trunk. The water conducting tissue is produced by the cambium which is a circle in mature dicots. If this were the trunk of a monocot like  most palms the water conducting vessels would be in bundles dispersed through the trunk.