Use Water to Control Root Growth Direction

Q. From your past articles I thought my Vitex or Chaste tree was not going to give me problems if planted near a wall. I was shocked this spring when I saw a 3” diameter root from our Chaste tree over 15 feet away heading toward a wall! I had it removed and the root cut out. You mentioned that Cottonwood trees can re-sprout from their roots after the tree is cut down. Can I expect the same situation with my Chaste tree?

A. Probably not. To my knowledge, Vitex roots will not grow back from the roots if the top of the tree is removed. It will sucker from its base if you do not remove the entire tree stump including a few inches below the soil surface. Removal is done by hand or using a stump grinder.

            Normally, this is a small tree that has few problems. It has few roots that grow on the soil surface so reading your email is a bit of a surprise. This tree is, however, notorious for invasive roots that grow into septic tanks and sewer lines when there is an opportunity. As with any tree, never plant it on top of or close to a leach field.

            I am guessing this tree root found something it liked in the direction of the wall. Like most plants, once they find a rich deposit of water and nutrients, roots grow vigorously in that area and can enlarge quickly.

            Roots do not grow into an area and explore it. They are not adventurers. They are opportunists. Roots grow most vigorously where there is water, air and nutrients. Plants such as Vitex, with few surface roots, grow near soil surfaces because they have to, not because they want to.

            Apply water and fertilizers in areas where you want roots to grow. Discourage root growth by not applying water and fertilizer toward problem areas.