Cut the four-year-old canes off at soil level, using pruning shears. Elderberries produce fruit on one- and two-year canes only, so the older canes no longer produce fruit.
Thin out the one- and two-year-old canes, removing the excess ones at their base. Leave between six and eight canes per plant, leaving an equal number of one-, two- and three-year old canes. Choose the strongest canes with the most lateral branching to remain, as these are the most fruitful.
Prune away damaged canes, leaving only the healthy ones. Cut off damaged or dead lateral branches from otherwise healthy canes, cutting the branches back to where they emerge from the main cane.
Inspect the elderberry bush throughout the spring and summer growing season. Prune back any dead or broken canes to the nearest healthy wood at any time during the growing season.