July 12, 2007
Olive Trees Inspection
On July 3, 2007, I inspected three Olive trees, Olea europa located at the newly constructed residence. I was contacted by Karen and informed that two Olive trees were dead or dying.
The Olive trees are mature old grove trees transplanted into the landscape, 15’ high x 15’ wide on average.
The trees have been in the ground for one year. Each tree was planted with the hole over excavated and a base of gravel was installed. Each tree has 2 vertical drains. Three Olive trees were in various stages of decline. The irrigation system seems to be over watering.
Olive tree located at rear yard fence. 15’ high x 15’ wide. Large root flare with 5 trunks, DBH 9”. 100% dead leaf on branches. Some broken branches. Vertical drains observation; 30” below finish grade, 12” standing water. The soil is sandy clay with an acid PH of 4.0. PH reading was obtained with a hand probe in the field. Tree is dead.
Olive tree located near back yard pool. 15’ high x 20’ wide. Large root flare with 4 trunks, DBH 6”, 90% dead leaf on branches. 10% of green leaves are at branch tips. Vertical drains observation; 33” below finish grade, 10” standing water. The soil is sandy clay with an acid PH of 4.0. PH reading was obtained with a hand probe in the field. Tree is stressed.
Olive tree located at corner of garage next to driveway. 15’ high x 20’ wide. Large root flare with 5 trunks, DBH 5”, 2”, 5”, 4”, 6”. 10% dead leaf on branches. Some broken branches. Vertical drains observation; 30” below finish grade, 16” standing water. The soil is sandy clay with an acid PH of 5.5. PH reading was obtained with a hand probe in the field. Tree is exhibiting early stages of stress.
· Replace. Remove all gravel and soil around old tree and replant with new.
Tree #1 & #2
· Pump water from vertical drains
· Reduce watering schedule
· The soil requires the addition of lime to bring it's pH level to 7.0-8.0 (alkaline).
· Drill or core 6 vertical 1” diameter holes around root ball + 24” away from root flare, take care not to damage large roots. This will allow oxygen to infiltrate the soil.
· Remove berm around trees and slope soil to atrium drains so surface water is carried away.
· Prune broken branches only, keep all remaining branches.
· Apply superthrive per manufacturer’s specifications.
Roots support the tree, store energy reserves, absorb water, and with the help of root-associated fungi, absorb elements that are essential for life. There are woody roots and non woody roots. The woody roots are large support roots and smaller fine roots, The non woody roots are non mycorrhizal or mycorrhiza— associated with fungi.
The anatomy of roots is basically the same as trunks. The roots have a vascular cambium, bark and wood. There is no pith in the center of roots. The roots usually have more parenchyma cells and fewer fibers. The distinction between growth rings is not as clear in roots as it is in trunks. Roots do not have a normal, colored, core of heartwood. The anatomical changes from trunk to root occur in a transition zone at the base of the tree. There is seldom an abrupt anatomical change from trunk to root. If there is a pith center, the section is trunk and not root.
Roots, like branches and twigs, also age and die. As roots die, boundaries form that resist the inward spread of pathogens. When non woody roots die, a corky periderm —boundary — forms that separates the non woody infected root from the healthy woody root.
Summary / Conclusion
Thank you for calling on my services with your questions regarding your Olive trees. The 3 Olive trees were in various stages of decline due to root rot brought on by standing water in the root zone. The one dead tree is to be replaced and the 2 other trees need to have the root zone free from standing water. The soil PH is acid and needs to be treated with lime to provide optimum growing conditions. The watering schedule needs to be monitored. With proper care, your trees should be able to compartmentalize the disease and remain healthy. In the future, a pathogen to be cautious of is; Armillaria Root Rot (Oak Root Fungus)Pathogen: Armillaria mellea
If you have any questions concerning this report or if I can be of further service to you, please call me at any time.
Craig de Pfyffer
Certificate # WE-6533A
Expiration Date: 6-30-2010
Although all the recommendations in this report are based on sound and accepted horticultural practices, the author cannot be held responsible for the final outcome of the recommendations, or any liabilities associated with this project. Tree inspections, in this case, do not cover internal cavities, structural defects, or diseases with non visible symptoms.
ENVIRONMENTAL DESIGNS ARBORIST
P.O. Box 247, Laguna Beach, CA. 92652 ·
Tel: (800) 811-3010 Fax: (800) 811-3014