The Depths of Planting

Root Flare on Tree Planted At Right Depth

This time of year will always find me answering questions at plant sales or speaking with students about the importance of planting trees. Unfortunately this year an unseasonal cold prevented me from speaking at either. I did manage to attend and was able to confirm the old saying that “ you have two ears and one mouth so listen twice as often as you speak”. While my voice was out of commission I was able to stand back take a few pictures and listen to one of my fellow arborists speaking with a group of 4 and 5 year olds. He, being unprepared due to my sudden laryngitis , showed true mastery in arboriculture by improvising a great presentation on trees, how important and present they are in our lives. Halfway through I croaked “ Whats in the bag?” and he pulled a small white spruce plug out of the paper bag he was holding. The children were ecstatic and without missing a beat he held the tree up side down and asked “ Do we plant a tree like this” to a gang shout reply of “ No” they all replied, flipping the tree. “ How about like this?”,the tree was now right side up and all agreed that “Green on Top” was the way to plant. So how do we go from this simple consensus to over half the trees in the average landscape being planted to deep?

The simple truth is if I you walked out your door and found a planted tree it would more than likely be planted too deep. At the mall,shopping center, park or many of my clients properties there are no shortage of these buried alive trees.

Trees grown in nature from seed are rarely planted to deep. Flooding, landslides and wind sedimentation can cause tree burial but it's rare. In our landscapes the most common culprit is planting too deep and settling after planting.

Trees almost universally flare out where the roots differentiate from the trunk tissues.

This basal flare should be your clue to correct planting depth. The flare should never be completely buried and should generally be at the surface or just slightly above. This translates to a centimeter or half inch or less above the surface of the soil. If you see a tree that looks like a pencil coming out of the ground, strait with no flare at the base it is likely planted too deep. Trees want to grow roots in a downward direction, this is called geotropism and ensures roots remain in the ground and not heading to the sky.

The process of planting a a tree or shrub often starts with a hole in the ground that is more suitable for a fence post or pit barbecue than a plant. Trees do best if planted in shallow lens like planting sites that are wider than deep. Care must be taken in most soils not to glaze the outer edge of the planting site by packing it while shoveling. Once you are done take the side of the shovel and break up the hard polished soil so the roots can easily penetrate it. If the tree requires staking once planted do so loosely and be sure to have a plan in place to come back and remove the stakes and wires once the plant has settled. If in doubt when planting trees contact your ISA Certified Arborist they are the go-to experts on tree planting and care.