Both bay laurels and tanoaks can spread SOD while most oaks are not infectious. Therefore, bay removal is typically aimed at protecting oaks. In the absence of bays, you may actually be able to facilitate survival of asymptomatic tanoaks, but only if their density is low (about 20 per acre). A possible plan of action may thus be to eliminate all medium-sized bay trees (up to 20 inch DBH) that are not in a riparian setting and to eliminate all infected tanoaks. You may then decide to leave a few well-spaced tanoaks (50 feet minimum from one another), ensuring none of them are within 30 feet of an oak.
Once down, spores from bay foliage will not travel nearly as far as they do in the canopy. The concern on the ground is that infested leaves, while still fresh, could have spores picked up during a wet event from soil splash onto the trunk of the tree. So, spread bay foliage in a thin layer in a sunny area that will promote drying. Be sure to not have foliage near the base of oak or tanoak trunks where soil splash/infection could occur.
The lab can, upon request, analyze wood chips at cost ($90 US dollars per sample). Testing would confirm the presence or absence of any known dangerous pathogens.
There are currently two options for injections:
- Chemjet® injectors (coil activated) – volume to be injected = 20 ml; 10% of current label dose; pressure 20 PSI (pressure of injector is already set)
- Arborjet® injectors – volume to be injected = 40 ml; 5% of current label dose; pressure set at 35 PSI
Injections should be done every 2 years. Every year you inject, stagger injection points 2 inches up and 2 inches sideways.
• As a rule of thumb, use one injection every 6 inches, with all injections at the same height.
• Start injections the first year as low as possible on trunk.
• Avoid injecting under branch stubs or punks.
• Injections should take 1-10 minutes to be absorbed. If they are absorbed in less than 1 minute, the material was not absorbed by vessels. If it takes longer than 10 minutes to be absorbed, the timing was not good for the treatment.
• Good days/timing for injections are warm and breezy days between 10 am and 3 pm.
• Leave injection holes unplugged.
