Great Question ! Now ask yourself a few questions. Do you want to keep the bed, is it still making berries, do you want to renovate or make a new bed? The best time to make a new bed in the spring. To get rid of side shoots you could bush hog or spray now, but you may kill too many plants. To renovate you could prune it back and see what you have in the spring then take the best plants and fill in the area you want to retain, Ssuggestions: dig down about 18 inches and make a border with tin or wood to keep the roots from spreading and grow the plants on a raspberry trellis so that you know which plants you are keeping and they are easier to pick. Doing this project use a heavy pair of gloves. Think how good those berries are going to taste, it will motivate you.
Delaware, KentCo. Master Gardener Beverly