I had a monti and birdsnest that were 6 to 9 inches apart. Both being fast growers I watched as they got closer and closer. I figured one would just kill back a little of the other. I get a call at work from my wife saying something to happening to the monti. By time I get home it is half dead. 24 hours later the whole thing is dead. Then I notice the branch of the birds best that touched it turning white. Within a few days the whole colony was dead except for one little brach. I never expected to lose both colonys.