According to an old Chinese proverb, “The best time to plant a tree was 20 years ago. The second best time is now.”
Friday is Arbor Day, so why not celebrate and plant a tree in your landscape or in your community?
Be sure to plant trees correctly so they live a long time. One of the biggest challenges that I see today in terms of proper planting has to do with planting depth.
The hole should be only as deep as the root ball and twice the width. Tree roots grow within the top 12-15 inches of soil and grow much further than the width of the tree canopy.
The root flare should be planted at or just slightly above ground level. The root flare is the area at the base of the trunk where the roots begin to flare out, away from the trunk. It’s the transition zone from trunk to roots.
The root flare should not be below ground, so find the root flare first and dig the hole according to this depth. The deeper the tree is planted, the less oxygen for healthy root growth.
We have learned over time that when the root flare is below ground, the tree has a tendency to develop secondary roots in order to try to survive. These secondary roots have a tendency to grow around the trunk and can eventually girdle (strangle) the trunk of the tree.
We also see secondary root development occur when too much mulch is applied around the base of the tree. Those of us in Extension call this “volcano mulching” because it looks like a volcano around the base of a tree.
Mulch should be no deeper than 4 inches and spread around the base of the tree but not up against the trunk.
Getting back to proper planting, there is a lot of discussion about to remove or not remove the burlap and wire basket (if there is a basket).
Years ago we used to leave the burlap and wire baskets on the root ball in order to maintain the integrity of the root ball. You don’t want it to break apart.
However, we found that synthetic burlap was not breaking down and the wire baskets were not rusting and both were causing some problems with root girdling in some cases.
The current recommendation is to keep the burlap and wire basket on the root ball until you get the tree placed properly in the hole.
Then, cut the burlap and any twine off of the top of the root ball, down to at least 12-15 inches. Cut the wire basket (bolt cutters work best) down past the first couple rows of wire, again, below the potential root zone.
After planting, water and take care of the tree in order to get it established.