Plant Health Care
1 Arastradero Road, Portola Valley, CA 94028650-326-8781

Plant Health Care

Our Plant Health Care program integrates state-of-the-art approaches to tree and shrub care, from roots to shoots. This program consists of scheduled diagnostic inspections that enable us to detect and treat problems before they damage plants. After each inspection we provide a comprehensive report of our findings and treat each landscape as necessary for harmful insects and diseases. We always suggest and implement solutions that are environmentally friendly.


Diagnosing plant problems can be done in the field. However, laboratory analysis is necessary to properly identify most disease problems. Treatment of symptoms does not always achieve the desired results. When a pest or disease is identified, then the treatment can be provided. Abiotic disorders do not require pesticide related solutions.

Targeted Insect and Disease Treatments

Controlling diseases like anthracnose or insects like tussock moth is often accomplished by spraying the tree canopy with the appropriate fungicide or insecticide. Both of these pests can cause defoliation of foliar canopies. This is not healthy for trees for the same reason heavy pruning is not beneficial. Defoliation decreases photosynthesis; the process in which a tree convert carbon dioxide and water to sugar and oxygen to feed itself and provide us with fresh air. This process occurs in the leaf, which is why we take special care in trying to protect the foliage.

Root Crown Restoration and Inspection

Restoration of the root crown to natural grade reduces potential for root rot infections. The inspections allow us to monitor and treat certain root pathogens and bark boring insects. We can also provide recommendations to improve cultural conditions in the tree environment.

Root Collar Excavation

Too often, established trees suffer from fill operations and excess soil is piled on the low trunk. This condition creates a favorable environment for root crown decays. During the excavation our specialists can excise decay and help the tree seal the decayed area more quickly. We have provided this type of service for over 90 years with much success.

Alternative Treatments

There are many alternatives to tree spraying including no treatment at all. Various forms of trunk injection, soil injection and trunk banding are available to control many insect pests and tree diseases. Insect Growth Regulators can be an effective way to prevent the growth and development of insect pests. Biological controls such as beneficial insects, nematodes, pheromone traps and sticky cards are all methods to manage disease and pest problems. Many other solutions are available as we continue to pursue alternative methods of disease and pest management to help the environment and maintain a vigorous urban forest.


Mulch and compost are natural ways to improve the root environments of trees. Some benefits of mulch include improved soil moisture holding capacity, long term soil fertility, soil aeration and soil structure. Put simply a good mulch and compost program will reduce the needs for water and fertilizers and can help improve the affects of soil compaction.