Growing Raspberries for the Whole Family

These perennials like plenty of water, and trickle irrigation works well unless you have sandy soil. One to two inches of water a week is a good rule to follow. Mulch lightly to improve organic matter, but be sure the mulch isn’t so thick that it restricts new cane growth. If possible, plant raspberries in full sun. Good air circulation is critical to prevent disease.

Two types of raspberries

There are two types of raspberries: summer-bearing and fall-bearing. The summer-bearing types need to be pruned every year, removing the old canes and pruning down the density of the new ones. Raspberry plants are unique in that they have perennial root systems that continue to grow, and they have a biennial cane system. The first year the cane is vegetative, and the second year it flowers, bears fruit and then dies.

Breeders at the University of Minnesota have been involved in raspberry evaluation for more than 80 years, and they introduced Latham, a popular summer bearer, in 1920. Boyne came along in 1960, and Killarney and Nova are more recent introductions.

A while ago, someone made a revolutionary discovery, according to Wildung — a plant that started to flower on the tip of the new cane. This find was the beginning of fall-bearing raspberries. Now most breeding programs are working with fall-bearing types because those canes can be cut down to the ground after harvesting and don’t require any other differential pruning. Mowing off the canes after harvest also eliminates the chance of winter injury.

Heritage was one of the first fall-bearing raspberry varieties, but it is too late for our short Zone 3 season. Autumn Bliss was a 1983 introduction from Great Britain, and it is two weeks earlier than Heritage. Wildung says the fall-bearing plants produce larger fruit than the summer bearers. To find out what type of raspberry is recommended for growing raspberries in your area, contact your county extension office or ask at local nurseries and garden centers.

Systems for pruning raspberry bushes

Two types of pruning systems are commonly used for raspberries. For our summer-bearing types, we planted four rows of raspberry canes about 25 feet long and 8 feet apart. We placed strong posts 10 feet apart in the rows with two sets of lateral wires, 3 1/2 and 5 feet high, on either side of the post. This system of training the plants is often referred to as the hedgerow or matted row system. We arranged the canes between the wires to prevent them from spreading.