Pine Tree Not Growing

This pine is struggling. Notice the open canopy, how thin it is.  It is either not getting enough water or it was rootbound at planting time. 

Q. Several pine trees on municipal park property provide privacy from people who frequent the adjoining park. All these pine trees have done well over the last 20 years except for one that is about half the size of the others. It’s in a perfect spot to provide privacy for me but doesn’t because of its size. It gets plenty of sun and is not overcrowded by other trees, but I don’t see any water for any of them. How do I help the little guy pine tree get to the same size as his big guy brothers?

This pine tree is getting enough water. Notice how full and dense the canopy is.

A. All those pine trees are irrigated, or they wouldn’t survive in our desert climate and put on decent growth year after year. The smaller tree could have a problem all its own, separate from the others.

Is it Rootbound?

            The fastest way to find out is to push hard on the tree trunk. You may have to push several times. After these many years, that tree should be solidly anchored into the ground. If it’s loose in the soil, the tree has a rooting problem and should be replaced. If a tree with this problem is not replaced, it will always be small and never grow regardless of what you do.

Plants that are rootbound can end up with strangling roots that choke other roots. These can be removed with they are young. Be careful when the roots are large.

            When you push on it, there should be no soil movement where the trunk enters the ground. If you do see movement beneath the trunk, the tree was “root bound” when it was planted and never became established in the surrounding soil. That would be unfortunate, but this happens too frequently to landscape plants grown in containers.

Plants left in containers too long can create root problems.

            “Rootbound” plants have roots that grow in circles inside the container. This root growth problem begins when plants are very young and is seldom a problem that develops when they are older.

            It is possible plants can become “root bound” if they are grown in a container which is too small for them for too many years. I suggest consumers don’t focus on the “largest trees they can find”. Smaller plants, that are healthy and growing rapidly, are always a better choice and will establish in the landscape faster.

Lack of Water

            Another possibility is a lack of water. Inspect the soil to make sure that irrigation is not the issue. If the plant is not root bound, water the soil under the canopy of the tree with a hose, sprinkler and mechanical timer for one hour, once a week. Do this during the summer months. Fix the irrigation problem of course but the extra water once a week will help push new growth faster.

            Fertilize pine trees once a year in the spring with a tree and shrub fertilizer such as 16-16-16 or 20-20-20.