Two years ago I planted a fresh row of raspberries at my allotment. I bought some autumn ones and was given several whipa of a friend's summer variety. The autumn ones have grown ok but the others went absolutely mad at the beginning of this year and spread amongst my berry bushes as well as way into next plotholder's patch. I could not believe how much they had spread along the surface of the ground when I went there in February/March this year. They grew to about 10 feet in height and despite this, the crop was sad. I am so embarassed about it.
SO does anyone know what I might have done wrong and what I should do. I am sorely tempted to rip the whole lot up and start again.