Living with oak trees:
Without proper care they can be loved to death
By Jeff Hunts
Special to theViewpoint
They grow in our yards,
our alleys, and even our streets. They reside in the rail yard. They emerge
from lawns, sprouting from acorns planted by jays and squirrels. They are
the oaks of Curtis Park-native Californians uniquely adapted to the rigors
of Central Valley life with hot, dry summers, cold, foggy winters, and the
gusty winds of seasonal storms. The expansive canopies of ancient specimens
shade our homes and turn unbearable August afternoons into fair weather
affairs.
And it is surprisingly easy to love these great creatures to death.
Anyone who has weeded volunteer oak seedlings from a flower bed knows that
starting the tree is easy, and in the fertile soils of an area once called
Curtis Oaks a young sapling rapidly develops a hardy root system. Oaks are
very adaptable to landscape conditions when young. But like many of their
human counterparts, as these trees mature they become set in their ways,
growing increasingly intolerant of changes to their environment and conditions
that differ from their long evolved preferences.
The best way to care for oaks both young and old is simply to be mindful
of the root protection zone. This zone is an area that extends half again
as large as the area from the trunk to the drip line (the horizontal reach
of the tree's canopy). This area should be maintained with as little disturbance
as possible, ideally with a leaf mulch allowing worms to aerate and loosen
the soil beneath the tree. Paving, compacting, trenching, and planting the
wrong greenery within the root protection zone jeopardizes the tree's long
term well being.
Unfortunately, our affection for lush landscapes and the water we generously
provide to achieve them are just the opposite of what a mature oak needs
to remain happy and healthy. While deep moisture is what nurtures an oak
through the year, surface watering can be a deadly menace. Damp soil around
the trunk of an oak during the warm months quickly leads to crown and root
rot that, left uncorrected, is a primary cause of oak fatality in our area.
An established tree usually does not need supplemental watering during the
summer and fall.
However, a mature oak that is use to regular drinks in an irrigated area
should not be forced to go on the wagon cold turkey. Ensure that the sprinkler
heads are not spraying water directly on the trunk, and reduce the amount
of water provided within the RPZ by about 20 percent per year over five
years. This allows the tree to adjust and grow deeper feeder roots.
It seems that the hot real estate market may be cooling along with the changing
of the seasons, but in an area as desirable as Curtis Park, the property
values remain high enough that many homeowners wanting more space are choosing
to add-on rather than buy-up. House remodels, especially with new foundations,
new utilities, and piles of soil and debris are another threat to established
trees.
If you are thinking of building near an oak, consult a certified arborist
about ways to minimize the damage that the project might do to the tree.
For instance, boring for new pipes and conduits instead of trenching can
preserve critical feeder and lateral roots.
Not only is the health of the tree a consideration, but so is compliance
with local heritage tree ordinances. Any native oak with a circumference
of 36 inches measured four and a half feet off the ground is protected by
law, and any activity that impacts such a tree-such as pruning or construction-must
be permitted by the Department of Neighborhood Services.
Native oaks, if cared for mainly by leaving them alone, can span generations.
With little effort, we can leave for our children and grandchildren a Curtis
Park that is the urban forest wonder that we enjoy today.
Resources:
The California Oak Foundation is an educational non-profit founded in
1988 dedicated to the preservation and care of native oaks. Detailed information
of oak care can be found at their website:
www.californiaoaks.org/
The UC Cooperative Extension has published an outstanding resource entitled
"Living Among the Oaks: A Management Guide For Landowners".
This eight page publication is packed with details information on oak
care, including a listing of landscaping plants that are compatible with
native trees. It can be ordered through:
www.ucanr.org/pubs.shtml
Sacramento Heritage Tree Ordinances can be found by searching for "heritage
trees" through the Sacramento Municipal Codes website at: www.qcode.us/codes/sacramento/
Sacramento Tree Services is now called Urban Forest Services and should
be consulted about heritage trees and street trees. Information and contacts
can be found going to: www.cityofsacramento.org/parksandrecreation/urbanforest/
Return
to Viewpoint Index
|