RE: planting under Calif. live oak

Kurt,

Thank you for clarifying some of the points in my post. Late at night I
sometimes take an abbreviated stab at things.  However, there is a big
difference in yard irrigation such as one finds in a garden and the water
that many of our riparian based oaks (such as some of the ones you
mentioned) find in  their native environment. Many of these oaks do need
substantial water, but most also do best if they find it in a deep water
table. When oaks are inundated, as you mention, this is usually in the
winter and spring, when ground temperatures are cool and root fungi less
likely to molest the tree.  Not so in a garden when supplemental water is
most likely to occur in the heat of the summer.

In comparison to your examples (which I am aware of), we should point out
that the oaks on the UC Berkely campus, which were succombing to disease,
revived and were saved during the drought years where water rationing
become the norm in the bay area.

I agree, my post was over general and too simplistic (it was almost
midnight!), but I still caution people about irrigating near their oaks.
They need to think carefully about conditions that occur their naturally,
what changes have been wrought on the oak, and act accordingly.  Oak trees
live a long time, and they do not like change!

My parcel is an excellent example. It is a 5 acre parcel with an irrigation
ditch that runs through it.  The previous owners used the ditch to irrigate
the lower half of the parcel.  The oak trees (a mixture of Blue Oak
[Quercus douglasii] and Interior Live Oak [Quercus wislizenii]) all slowly
died on the irrigated half.  It took them over 20 years, but when we bought
the parcel two years ago, the last few large trees on the irrigated half
were too far gone to save.  The upper, non-irrigated half appears to have
lost no trees during that time. Only one isolated anecdote, I know, but it
illustrates a point.

The Sunset lists of Plants to plant under oak trees half to be taken with a
grain of salt, because many of the plants are only suitable to be planted
at dripline as they require too much sun to grow successfully under the oak
canopy.

Kay, there is a small booklet put out by the California Oak Foundation
entitled _Compatible Plants Under and Around Oaks_.  You may find it
helpful. (Pretty specific title, huh.)

Rebecca Lance

>
>Water is NOT detrimental to all native oaks.  In fact, the greatest stands
>of Valley Oak (Quercus lobata), Interior Live Oak (Quercus wislizenii), and
>California Black Oak (Quercus kelloggi), are always associated with the
>presence of water.  In riparian areas, these trees often grow with their
>roots actually IN the water.  In the "tall forest" (Valley Oak riparian)
>area of the Cosumnes River preserve, the Valley Oaks are inundated annually.
>The last big flood there left a water mark 16 feet up on the trunks of the
>trees!  The water table along the river is practically at the surface, but
>the trees flourish.  At Oak Grove Regional Park in Stockton, part of the
>park was left in its "natural" state, while other parts were planted with
>grass and watered regularly.  During the last big drought, only the oaks
>which were in, or bordered on, the grassy, regularly-watered areas survived.
>Hundreds of centuries-old oaks in the "natural area" were allowed to die.
>At Oak Park in Stockton and Micke Grove Park near Lodi, large groves of
>centuries-old oaks have been underplanted with grass and regularly watered
>for 75 years with no observable ill effect on the trees.  There may be some
>native species of oak that don't like water (Blue Oak (Quercus douglasii)
>comes to mind.  Also, some of the scrubby or desert species), but it's
>definitely not true for all of them.
>
>Kurt Mize
>Stockton, California
>USDA Zone 9
>
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