Prune the raspberries in early spring before they begin growing again. Cut out dead and damaged canes. Remove any canes with a diameter of less than ¼ inch. Trim off the tips of the remaining canes, removing the dead portions at the tip.
Fertilize the plants in early spring before they begin producing new growth. Apply 4 lb. of a 10-10-10 blend to every 100-foot row. Spread the fertilizer in a strip down the row, 2 feet away from the base of the canes. Water immediately after fertilizing.
Water raspberries once weekly when growth resumes in spring. Provide 1 to 2 inches of water at each irrigation so the top 6 inches of soil remain moist. Raspberries tolerate some drought after the fruiting cycle completes.
Spread a 3-inch layer of sawdust mulch around the base of the raspberry plants. The mulch suppresses weed growth and helps moisture remain in the soil.
Trim the raspberries after harvesting the berries in summer. Cut out the canes that just completed fruit production, removing them at soil level. Leave the new canes in place as they produce fruit next year.