Tree Staking and Palm Trunks

Make sure when you stake trees to give them at least six inches to flex in all directions so they can grow strong. (brizmaker/Shutterstock)

Q: We planted some small trees last year and this spring. We tied stakes to them to hold them up. We tried untying some of last year’s trees, and they seemed to be wiggly, so we tied them back up. How long should trees be staked after planting?

A: You didn’t say how tight the tree was tied, but I am assuming that the tree was tied too tightly. The ninth video in the “Trees and Shrubs” playlist on the Greener View YouTube channel will answer all your questions.

Let me summarize the video here. Swaying in the wind causes plants to produce lignin. Lignin cements cellulose fibers together, making cell walls stronger. A wind-blown tree will be shorter and sturdier and have a thicker trunk than a tree that is not in the wind or that can’t flex in the wind. Trees allowed to flex in the wind also develop stronger root systems.

Stakes and guy wires must allow the tree trunk to flex at least six inches in all directions. If the tree is rigidly held in place, it will not develop a sturdy trunk or the strength to stand by itself.

If a tree is loose in the pot or in the hole after planting and needs to be staked, the stakes should be removed after one year. Make sure all materials that wrap around the trunk are soft and won’t damage the trunk.

Q: We are building a deck, and part of it will wrap around an oak on one end and a palm on the other end. We were told that the hole in the deck for the oak had to be created so that boards could be removed in the future to allow the hole to expand. We were told that the hole for the palm would not need to expand. I don’t understand why the palm trunk won’t get thicker. I would like to create a hole that can expand for the palm. What do you think?

A: You can create an expanding hole if you want to, but the palm trunk won’t get substantially thicker. Someday, you may want to replace the palm with an oak, so by creating an expanding hole now you have your bases covered.

Trees like the oak create new trunk tissue each year. We see that when we count the rings on the tree. Palms are monocots like grass and bamboo.

They grow differently. Stems of juvenile palms (those which have not yet achieved their maximum diameter) elongate very slowly and may even stay underground, expanding in diameter with each new leaf. The result is that palm stem bases are V-shaped, with the point of the V corresponding to the earliest stem tissue of the seedling. Once a juvenile palm stem reaches its maximum diameter, substantial vertical elongation of the stem begins, and further stem diameter enlargement essentially ceases. This explains the almost constant diameter or cylindrical shape of the trunk that is often seen in palms, unlike in ring-forming trees.

The swelling observed at the base of the stem in some species of palms is typically the result of new root development within the stem, although cell enlargement or lignin deposition can also contribute to the swelling. So if your deck is not too far off the ground and the palm is one that expands at the base, you may need an expanding deck hole.