What is the proper way to prune summer-bearing red raspberries in late winter/early spring?
Summer-bearing red raspberry varieties include ‘Latham,’ ‘Boyne,’ ‘Killarney,’ and ‘Newburgh.’ All summer-bearing red raspberries should be pruned in the same manner.
In March or early April, remove all weak, diseased, and damaged canes at ground level. Leave the most vigorous canes, those approximately 1/4 inch in diameter when measured 30 inches from the ground. After thinning, remaining canes should be spaced about 6 inches apart.
Also, prune out the tips of the canes which have died due to winter injury. Cut back to live tissue. If the canes have suffered little winter dieback, remove the top 1/4 of the canes. Cane-tip removal or “heading-back” prevents the canes from becoming top heavy and bending over under the weight of the crop.
To obtain maximum yields, red raspberries should be confined to a 1- to 2-foot-wide hedgerow. Shoots growing beyond the 1- to 2-foot-wide hedgerow should be dug up and destroyed using a rototiller or spade.