It’s time to sharpen up the pruners and head to the raspberry patch for a bit of midsummer gardening.
Raspberries grow long stems (canes) that are biennial, meaning they produce foliage the first year, flowers and then fruit the second year. The second-year canes then die after the fruit is harvested.
The specific pruning technique for raspberries depends on which type you’re raising. Summer-bearing red and yellow raspberries should be pruned to remove all old fruiting canes completely down to the ground.
Everbearing raspberries produce a summer crop on the canes that fruited the previous fall. Remove these canes after the summer crop is harvested. Some growers prefer to sacrifice the summer crop for ease of spring care and to create a larger fall crop. In this case, no summer pruning is required; all canes are mowed off in spring.
Black and purple raspberries benefit from two types of pruning technique. Like other raspberries, remove the fruiting canes after harvest is complete. Then tip-prune the top 3 to 4 inches of the new 1-year old canes to encourage more branching, which should result in more berries.
While you’re pruning, you’ll probably notice that your raspberry plants are propagating like bunny rabbits! Red raspberries tend to produce small plants growing nearby that come from the roots of the mother plant. These new plants are called suckers and can be divided from the mother plant with a sharp spade and replanted in the desired location (could be your neighbor’s yard!)
Black and purple raspberries often have canes that are so long the tips have bent over to the soil and may be forming new roots if the soil is moist. Covering the tips with 2 to 4 inches of soil will help encourage rooting. Next spring, the rooted tips can be severed from the mother plant with a sharp spade and replanted.
Keep in mind that older raspberry plantings may be infected with virus. Propagating from virus-infected plants will pass the virus on to the new planting. Check your plants for signs of disease (yellowing, spots, wilting) before propagating.