Larry Sagers: Prepare soil, prune to reap raspberry rewards

Published: Friday, March 18 2005 12:00 a.m. MST

To grow delectable berries like these, you may need to plant in raised beds or berms if your soil is too heavy. (Larry Sagers) To grow delectable berries like these, you may need to plant in raised beds or berms if your soil is too heavy. (Larry Sagers)
I recall a trip I took as a young Boy Scout to the mountains of Colorado. As we hiked the hills and explored old ghost towns, we also grazed on wild raspberries. Although we had packed lunches, we brought them back untouched because we ate our fill of those delectable berries.
Growing berries in Utah requires some attention to detail. Our soils and climate are extremely variable, so you will need to find what your soil texture, pH and salt levels are before planting any berries.
Raspberries prefer rich, well-drained, organic soils. Heavy clay soils make them more susceptible to root rot and iron chlorosis. If your soil isn't in good condition, add 2 to 6 inches of coarse organic matter as well as 4 to 8 cups of 21-0-0 fertilizer per 100 square feet to help break down the organic matter.
Growing raspberries in Utah requires preparing the soil before planting. (Larry Sagers) Growing raspberries in Utah requires preparing the soil before planting. (Larry Sagers)
If the soil is too heavy, it might be easier to create raised beds or berms.
Buy certified, virus-free bare-root plants from a reputable nursery. Purchase your plants as soon as possible and plant them immediately. They are cold hardy, so frost will not hurt them. If you wait until later in the summer, potted plants are much more expensive and are harder to establish.
Plant raspberries 2 to 3 feet apart and allow the suckers to fill in the rows. Keep the raspberry rows about 18 inches wide, and leave enough room between rows to cultivate. Raspberries love mulch, and a good layer of it will help keep down weeds.
Water your raspberries after planting them to get them established. After that, water them deeply and infrequently. They do not like the same watering schedule as lawns. Typically they will grow well with 1 to 1 1/2 inches of moisture per week. Increase this to 2 to 2 1/2 inches per week when the plants are fruiting. Drip or soaker hoses work well, and a mulch layer will help conserve moisture.
 () ()
If you already are fortunate enough to have raspberries in your garden, it is essential that you learn when and how to prune them. Prune them now, before they start to grow. Remember that raspberries are perennial plants, but the canes are biennial, meaning they live only two seasons.
The two types of red raspberries are June-bearing or everbearing. Keep in mind that yellow raspberries grow the same as red raspberries and differ only in color. June-bearing plants produce a heavy crop of berries from June through early July. They grow vegetatively the first year, then produce fruit the following June. After the canes produce fruit they die.
June-bearing raspberries are easy to prune. Simply cut out the dead canes. The gray stems with peeling bark are dead and should be removed after they produce a crop. If you cannot tell which canes are dead, watch the buds to see which ones start growing, and then remove the others.
Leave the live stems because if you remove them, you'll remove the fruiting wood, which removes your raspberries. Never prune June-bearing raspberries to the ground because you will never get any fruit.
Everbearing raspberries produce two crops, one in June and one in the fall. There are two ways to prune this kind of berry. The first is to prune them the same way you prune June-bearing raspberries. Additionally, you should prune the live canes on everbearing raspberries at about 4 or 5 feet tall.
An alternative method is to prune the entire patch down to 2 to 4 inches every year. This method eliminates the June crop, so your fruit production is limited to the fall.
The two most commonly planted varieties are Canby and Heritage. Canby is an almost thornless variety, which is a favorite in the Bear Lake area. It is a June-bearing type, as are two other favorites, Latham and Newburgh. Heritage is an everbearing type that is also a local favorite.

Larry Sagers is the regional horticulturist at Utah State University Extension Service at Thanksgiving Point.

Copyright 2015, Deseret News Publishing Company