Raspberry cane advice

You need new growth - the plants have to grow new canes for next spring or for autumn, depending on what type you have.
If you don't want suckers coming up outside the bed, chop through the roots as soon as you see them - or dig them up and treat them as free plants that you can plant elsewhere.- or leave where they are - as I do.

Hi Veggie

Autumn fruiting, my hoping was the cardboard would suppress weeds but allow the raspberry's through?