Four new Japanese Zelkova trees were just planted at the in four foot square containers.
While the containers were going to be self-watering, I determined that was not a good way to handle trees that should last for five or six years (or beyond!). In this case, the self-watering consisted of a container at the bottom that relied on a wicking action to move water upward into the root area.
This is not optimal for trees. Trees need periodic soaking with a chance for the soil to dry out a bit in between. Also, the water flushes out toxins that would otherwise build up in the soil and cause root problems.
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Instead, we drilled drain holes in the bottom of the containers, installed crushed stone and a barrier of landscape cloth, and then planting soil. We mulched the trees with sweet peat in the best possible fashion. The planting surface ends well below the rim of the containers allowing room for a good soaking.
We chose the containers because they are of a size that will allow good root growth so the trees can remain for a number of years without becoming root bound. The J. Zelkove has a vase shape so it will cause minimum problems to pedestrians and vehicles. I have included a file photo of a zelkova in fall foliage.
