The time to protect mature trees on your property from damage during a house remodel (if you decide to save the trees), is before construction starts. Otherwise, you could end up paying many thousands of dollars to replace trees that are injured or killed by heavy machinery or other mishaps.
When roots are compacted by heavy equipment or severed by trenching, chances are you won’t see the damage immediately. But injured roots are often unable to take up water, air or nutrients, and this results in the decline and eventual death of the tree, even years later. Disease organisms or pest infestations that enter unhealed wounds can also kill the tree in time.
Avoid building within the root zone of a large, established tree. Allow at least one foot of space between the trunk and the structure for every inch of trunk diameter measured at 54 inches above soil level. Learn where any new underground lines will go and reroute them away from trees, if possible. If it’s not possible for contractors to work outside the root zone, up to one-third of a healthy tree’s roots can be removed without severely harming the tree, but its growth and health may be set back for years.
If heavy equipment must be moved over the root zone, cover the area from the trunk out to the drip line with a 12-inch-thick layer of wood chips, then top the mulch with sheet metal plates or plywood sheets to minimize soil compaction. Make sure your contractor knows your wishes regarding your trees and will convey your wishes to workers; the best way to do that is to spell them out in the remodeling contract.
If you do sustain some damage to any of your mature trees, here are some tips you can follow as to the cause of damage: If you see broken branches, large branch stubs, left by breakage or careless pruning, seldom heal over. Removing a tree’s top to preserve the view or keep it out of the wires makes it ugly; weak new growth follows. Most roots are within the top 24 inches of soil and can extend beyond the dripline; digging trenches for utilities too close to the trunk can seriously injure or sever tree roots. Nonporous paving under the canopy can prevent water and air from reaching roots. Even 2 inches of fill dirt, if it does not have good drainage, can smother roots. Spilling wet concrete, paint or solvents within the root zone can poison the tree. Heavy equipment or pallets of pavers can squash a tree’s shallow surface roots.
Here are some protective measures you can take to prevent damage: If the canopy needs removal to make way for heavy equipment, hire an arborist to do it. Instead of topping, cut selected branches back to the lower lateral branches. If you need to work close to the trunk, prop hay bales against it to protect the bark. Use rope to tie thinner, flexible branches up and out of the way of trucks and machinery. Put a fence around the tree as far outside the dripline as possible; lay plastic tarps to keep out contaminants.
If you are planning to plant new deciduous trees around your home, why not follow the sun’s path for planting? The morning sun comes from the east, so trees planted close to the south and east wall of the house shade and cool the interior, preventing heat from building up indoors. The afternoon sun can be burning hot in summer, forcing air conditioners to work full strength to cool off rooms; plant trees on the west side of the house to block afternoon sun and cool the house interior, and let the northernmost tree directly shade the windows.
How much can you save in energy by planting deciduous trees? How much money can you save by planting trees around your house? Using a model of a 2,500-square-foot unshaded house in our valley, a computer program at the University of California, Davis, predicted that shading the house’s east and west sides (including windows) could reduce energy use for air conditioning by as much as 40% annually. That is a whopping good savings, if you ask me.
If you have any gardening questions, just text or call me at (916) 719-9020.