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1. How did the tree survive for so long before it looked stressed?

In all reality this tree should have succumbed many years ago. Not only was the site filled with 3-4 ft of crushed rock and gravel, but San Antonio Creek was also channelized even before that, taking away one of the tree's sources of water. However, man-made intervention inadvertently kept this tree alive: the porous gravel fill, supplemental irrigation, and adding mulch under the canopy all contributed to keeping the tree going.

Typically, Coast Live Oaks once established do not need supplemental irrigation and can in fact be harmed by too much water. In 2005 with the completion of the Native Oak Grove, supplemental irrigation ceased. The 2004-2005 storm season was an exceptionally wet storm season with rainfall totals being 23 inches above ‘normal’. This volume of water really provided a boost to all the newly planted oaks and the large oak.

The ensuing years produced largely below average rainfall, and without the supplemental irrigation to which it was accustomed, the tree began to show stress from drought conditions.

2. How often are you watering the tree?

During the hot months the tree is receiving supplemental water about once per month. Once the rainy season comes, the supplemental water will be cut back.

3. How long will the tree be fenced off?

The perimeter of the oak tree is temporarily fenced off with a plastic fencing material, which will be in place indefinitely until the tree shows marked improvement. This serves as a barrier to keep the public out of harm’s way from potential falling branches or limbs, or falling into excavated area. Additionally, the barrier is meant to keep human foot traffic (soil compaction) off of any feeder-surface roots, and to keep any climbers out of the tree.

The picnic tables that once sat under the big oak tree have been relocated to shady spots throughout the Oak Grove. There are also picnic tables and benches interspersed throughout the Wilderness Park. We invite you to come enjoy your lunch in the oak grove or park, or take a seat on one of the benches provided in the Water Wise Demonstration Garden.

4. Why are you not doing more to save the tree?

The tree took a long time to show stress and it is going to take some time to show some improvement as well. The district has been monitoring the tree's health since 2012. The district excavated the tree trunk to expose the root flare and has been giving it supplemental irrigation as recommended by professional arborists.

Regarding the tree's aesthetic appearance, trimming dead branches in the summer would cause the tree's living branches to be sunburned, so the district will hold off on any trimming until the sun is less intense.

5. Will the tree survive?

We are not sure if the tree will make it through this period. Our staff is closely monitoring its progress. The tree's feeder roots have grown back to the surface and there are still areas of growth within the canopy.

CBWCD is passionate about the care and recovery of this magnificent tree. The district continues to provide the care the tree needs to ensure the highest percentage of survival. We have not thrown in the towel on this tree!

6. Won't a tree die if the soil grade is changed?

Typically, yes. The additional soil materials will essentially suffocate the trunk from lack of gas exchange, create a moist habitat for deadly bacteria and fungal infections, and bury feeder roots, limiting the ability to transport oxygen, water and nutrients.

However, it appears this grade change happened with primarily rocks and gravel, which formed a porous cover and allowed moisture to get through to the tree's roots. In addition, a lawn and sprinkler system was created around the perimeter of this tree that allowed water to feed the tree even as it was being compromised and struggling to adjust to its new environment. These actions have allowed this tree to survive where in most cases it would have died within a year after the grade change. Oxygen, water and nutrients were provided, though via a somewhat compromised means. Additionally, with this porous fill, the buried feeder roots were able to grow back to the existing surface grade within some degree.