I had septoria leaf spot on my bosyenberries pretty bad in late summer and just a little bit on one of the marionberries. I think my watering practices contributed to the problem but have read that boysen and other trailing varieties are more susceptible than other blackberry / hybrid varieties. I sprayed them with a copper solution before they leafed out and plan to use drip irrigation this year.

Scott,

I've tried sanitation (cutting out galled canes) but I never noticed it helped any. Perhaps there are just too many wild blackberries here which provide alternate host sites.

I'm more or less living with it. They don't seem to gall all the canes here.

I wonder if copper or lime/sulphur is better for septoria leaf spot. In looking for controlled studies I could not find anything. Since I already did a sulphur I will also do a copper in a few weeks. One site recommended 3 copper sprays in the spring.

I don't have many wild blackberries around so I will try removing the galls for a bit and see how it works.

Scott

In my berry patch septoria mainly takes hold on the over-wintered leaves and new growth is nearly unblemished through the fruiting season.

Larry, my bigger septoria problems could be due to greater stress on the plants. They don't like my heat very much. I noticed that the growth completely stalled in the hottest part of the summer, they didn't budge.

Scott