Posted on by tonytomeo

Straight And Narrow For Trees

30731thumbIn the wild, trees do just fine without any help from anyone else. They certainly are not stupid. Their roots disperse for adequate stability. Their trunks grow upward as limbs spread outward for adequate structural integrity. Trees only need help in landscape situations because they are expected to perform so unnaturally. From the very beginning, their trunks are bound and their roots are confined.

While they are growing in the nursery, trees are bound tightly to stakes to keep their trunks straight. Unfortunately, this binding inhibits natural development of trunk caliper. Since they can rely on stakes for support, trees do not waste resources on developing the strength of their own trunks. The various eucalypti are particularly sensitive, and can bend over to reach the ground when unbound.

Roots are confined to cans (pots) or boxes because that is how trees are grown in the nursery. Even in regions where trees are field grown, roots must be severed when trees get dug and moved. Many types of trees do not mind much, and are eager to disperse roots into a new landscape as soon as possible. However, oaks, pines and many others do not recover as efficiently from confinement.

Once in a new landscape, most trees need to be staked to recover from being staked and confined in the nursery. New sturdier stakes that extend below the confined root system into soil below should stabilize newly planted trees. This is particularly important for evergreen trees that will be blown more by wind than bare deciduous trees, and particularly because most trees get planted in autumn and winter.

These new stakes should be installed a few inches away from the tree trunks so that they can support the trunks loosely when the tightly binding nursery stakes gets removed. To prevent abrasion, new straps should be somewhat loose, and cross over between the trunks and stakes. A pair of opposing stakes, with straps supporting in opposing directions, is sturdier than a single stake. A few straps may be necessary.

The new crepe myrtle trees in the picture above remain  bound to the stakes that they were grown with in the nursery. Sturdier stakes that can support the trunk in a less constrictive manner have yet to be installed.

Posted on by tonytomeo · 2 Comments

Scofield Tree Update

P71212+KThe sad little Scofield Tree in Felton Covered Bridge Park did not do much this year. (https://wordpress.com/read/blogs/135014809/posts/322 and https://tonytomeo.wordpress.com/2017/12/02/felton-covered-bridge/) In fact, it grew only about five inches taller, so is now only about four feet tall. The damage from the weed whacker really set it back. Growth was healthy on the side shoots, but that growth will need to be tucked back to promote apical dominance. The good news is that the vigor and health of the foliage of the sideshoots indicated that root dispersion was likely adequate to sustain healthier and normal vigorous growth next year.

Although the sideshoots will get tucked back to limit their competition with vertical growth of the main trunk, the stubble will remain to promote caliper growth of the trunk.

The trunk will be bound like a tree in a nursery; and the bound trunk will be staked for stability. Binding outside of a production nursery may not seem to be horticulturally correct, but is necessary for a straight trunk. The staking is done more to protect the tree in such a high traffic area than to support the tree. It would be better for the tree to do without binding and staking so that it can learn to support its own weight. Once the straight section of trunk is taller than about six feet, the bindings will be loosened, and eventually eliminated as the trunk lignifies into form.

A bit of fertilizer will be added to the soil around the tree before the last rains of winter. This might seem like cheating, bur for right now, the tree is too small to be safe in such a high traffic area. It will also be irrigated occasionally after the rain stops. It does not get much water, but will get enough to keep it vascularly active through the growing season. Too much water promotes shallower roots, which might damage the nearby concrete curbs and asphalt pavement. Valley oaks naturally disperse their roots very deeply, so the curbs and pavement should be quite safe for a century or so.