The advent of summer brings with it the thoughts of renewal and plans to re-landscape the yard. If you have mature trees in your yard here are a few tips to make sure they survive the proposed changes.
One of the common mistakes people make about their tree is that they wrongly assume since they have a mature tree it has a tap root that goes way down into the earth to some secret source of water, and therefore doesn’t need any additional water. So one of the first things they do in preparation for the new project is to turn off the irrigation system, since it, along with all the plants and lawn, are going to be replaced anyway. What they don’t realize is that the tree, over the years, has adapted to the watering it has received, so once it is eliminated the tree becomes drought stressed. Then to add insult to injury, while the new irrigation system is being installed, (usually requiring trenching for the new lines), and the soil is tilled in preparation for the new lawn the tree’s tiny absorption roots are destroyed. On top of all this unknowing abuse, most people re-landscape in summer when it is hot and the tree suffers more. We get called a year or two later, when the tree is in major stress, thinning canopy, under sized leaves along with scattered dead branches. At that point there is not much we can do. Unfortunately there is no way to glue roots back on to a tree.
Therefore, the best way to protect your mature tree during a yard renovation is to include tree preservation into your planing stages. Here are a few tips to help ensure your mature tree survives the renovation project:
Tip #1 – Disregard anything you read on the internet (including this blog) or what the local nursery tells you about your tree. Nothing can substitute for having a knowledgeable arborist visit your site and see the tree in its natural setting and give you good advice about how to protect it during construction. There are so many variables to consider, species, the over health, age, and specific soil conditions that there is no way someone who hasn’t seen your site can give you accurate advice. The following tips are guidelines, based on generalities. In our experience we have seen trees do amazing things that defy all generalities! So Tip #1 is to schedule an appointment with an ISA Certified arborist to visit your home and discuss your plans about re-landscaping around your mature tree.
Tip #2 – If your mature tree is damaging existing hardscape that will be replaced consider adapting the new hardscape to accomanadate the tree rather than making the tree adapt to the hardscape. For example if the tree is pushing against a fence, re-adjust the fence so that the tree is incorporated into the fence. If its roots are lifting a sidewalk or patio consider re-designing the patio away from the tree to give the roots more room to grow. The more you can do to allow the roots to be undisturbed within the dripline of the tree, the better.
Tip #3 – Be sure to water your mature tree, before, during and after construction. The more hydrated your tree is before construction starts the better it will be able to survive. Be sure to water the tree during the project. Ideally you want to water 360 degrees around the tree, from the trunk out to the dripline, down to a depth of 10″, at least once a month especially during the hot summer months. The same holds true after construction. We find an overhead sprinkler, that you can move around the tree works best. Since every soil is different the first time you water you will need to monitor the watering to determine how long to leave the sprinklers on. Find something stiff, like a piece of rebar, about 12′’ long that you can insert into the soil around the tree. If it slides in easily, the ground is moist down to the depth you want. If it stops half way, it means the soil is still dry and compacted and needs more water.
Tip #4 – Don’t prune your tree before construction without consulting with an arborist first. It’s pretty much a given that the tree will suffer root loss during the course of construction and some species of trees can tolerant a significant amount of root pruning, but there are consequences that come in the form of branch die back. Do not try to predict which branches will die back or think you can change the root zone by pruning the tree and reducing the dripline. Allow the tree to tell you which branches it is going to lose by waiting 6 months to year after the project to prune the tree. Remember, the leaves are what feed the tree and provide the energy necessary to cope with construction impacts, therefore you want to leave as much foliage on as possible so the tree has the resources necessary to survive.
Tip #4 – Don’t trust your landscaper to know how to protect mature trees during the landscaping process. John started out as landscaper and he never once thought about the existing trees as he rototilled for new lawns and trenched for new irrigation lines. All he remembers is that the trees produced a lot of roots that only got in the way and clogged the tines of his tiller!
Tip #5- Go back and re-read Tip #1. After reading tips 2-4 hopefully you will see the value of having an arborist visit the site as they can
1) Identify the species and health and condition of your tree
2) Evaluate your present watering program and make suggestions for changes
3) Create a tree protection plan for your specific project