Thanks for the kind comments.
Your very welcome.
In your experience, why do you think that they don't do well in shallower pots?
In general, I have found that they have a weak root structure that seems to be inherant to this species of Prunus. I have two that I have managed to keep alive since 1993. Neither has developed what I would call a substantial root system.
I have lost six or seven more to the borers and a few more to SDS, (sudden death syndrome) over the years while planted in shallow containers. I believe these SDS failures were due to heat. My Prunus angustifolias do not like to have their roots baked in small, shallow containers. Since I started using deeper pots, the SDS problems stopped.
How can I identify the borers? I don't think I have ever seen an attack from them on any of my trees. I have a systemic that I can start using when it leafs out.
Borers are stealthy little devils. There does not seem to be a distinct pattern to their attacks. One of the signs is the sudden loss of a branch that appeared to be healthy several days earlier. Another is sap oozing from a small round hole in the trunk or branch. Sometimes there is no outward signs if they get under the bark in an obsure place.
In regards to borers, the best defense is a good offense. Check the label of your systemic to see if it works against borers and if it can be used on Prunus. If so, use it regularly and you should be ok.
I use Lindane regularly during the height of borer season and that seems to work for me.
Regards,
Paul