Fall- The short and long term impacts of construction on our existing landscapes

The construction industry is hot again. I’m seeing a lot more holes in the ground and permits are taking longer to be issued. I wonder, does anyone ever stop to consider how all this construction and activity affect the existing landscapes and native or mature plant material that has been marked to stay on site or “worked around”.

 

As a goal we aim to always do the best for our clients and their landscapes. I will admit though, in the past we have rushed onto a site without fully considering or understanding our impacts on the existing plants and trees. We are always learning though and I am determined not to make the same mistakes twice.

 

The following are some things you should consider if you are going to be beginning a construction or remodel project on your home:

 

Root zone damage

If you are going to stick a shovel in the ground or drive any heavy machinery on your property you will be impacting the “root zones” of the plant material in your work area. The root zone of most trees is effectively the “drip line” or the outer perimeter of the widest branches. The root zone width and depth can be affected by soil type, but for the purposes of this article let's assume that the root zone is consistent with the drip line. I have always been advised by arborists and professionals that I trust to stay out of this fragile area to best preserve plants and trees for long term health.

 

 

The best way to ensure that the root zones will be protected during construction is to mark the trees you want to save and install temporary posts and fencing to keep the people who don't care about your trees from disturbing their roots. I have seen professional bidding documents where architects actually required that chain link fence be installed to protect specimen plant material. If you must dig, there are tools that can actually dig around critical roots and or utilities. These are very specialized tools. Contact us for more information if you think your site might necessitate this special digging.

Dave Firman of firman tree service noted that he meets frequently with clients that have completed remodel or new construction projects 2-3 years prior. They often call him to come out to remove trees that have been impacted by construction. Often this suble root or other damage takes years to unfold. An expireinced green industry profesional should be able to identify many trees that may have sutained injury durring construciton.

Dave noted that sometimes construction impact is unavoidable. In these cases we, as professionals, need to be honest with our clients about the fact that it will be less expensive and invasive to remove the affected trees at the time of construction than later. Dave noted that in the event of severe root damage temporary or long term irrigation measures can lessen the impact and possibly save the plant.

If invasive digging does take place Doug Boor of Mountain Top Tree Company notes that root pruning can be beneficial. Root pruning is taking the mangled or broken ends of the roots and getting a clean cut on them using hand pruners or a hand saw. In conjunction with a good aftercare program this practice allows the roots to heal and start anew.

 

Compaction:

Whether inside the root zone or beyond, consideration should also be given to the effect of compaction on your plants and soils. Compaction can come from the obvious (heavy machinery, vehicular traffic) or the less obvious (heavy foot traffic, small lawn care equipment). Compaction affects your plant material in a few ways. It affects the plants ability to continue to expand its root system, can damage an existing root system, and limits the ability of water and nutrients to penetrate the soil and reach the roots.

The effects of compaction are sometimes fixable after the fact although prevention is the best method of protecting your plant material. Contact us for more information if you think you have a compacted site.

When root zones MUST be driven over we would recommends installing a layer of wood chips, plywood, or using construction matts over the affected root zone to spread the load and lessen the compaction in these areas.

 

Limb damage:

When dump trucks, sky tracks, excavators or any other equipment taller than 6’ come on site, care should also be taken to protect overhanging limbs on existing trees. You may be thinking “what could damaging a few limbs do?”.  Breaking, scaring, or shearing limbs especially in the non dormant season can lead to life threatening disease or infections. Especially to trees like oaks that are susceptible to oak wilt and should not be pruned or cut during the non dormant season in our region. If limb damage does occur a clean flush cut is recommended. The old school tactic of painting the wound is not. Limbs can be tied to the stem or pre-trimmed to prevent further damage to trees and shrubs.

 

 

Drainage damage:

If you or the previous homeowner of your home had the foresight to install a drainage system to protect your home and landscape from ground and storm water you should also consider how digging and compaction will affect that system. One crushed pipe can affect a major network of drainage uphill of the damage.

 

With foresight and a little planning these issues can be avoided. Consider that some trees and plants are literally irreplaceable. Like a precious piece of art some trees are irreplaceable either because of their size, location, or character. It sounds like overkill but some plants or trees are more than just that. Some are where you buried your dog or where you had your first kiss. Some plants are landmarks. Think about the fact that, the tree that’s on the chopping block or tagged to be cut down could one day be that tree for someone else.