By Heidi Rader
Most gardeners I know tend to be fairly haphazard with their raspberry patches, myself included. This laxity works because raspberries tend to spread on their own (much more than you might want in some cases) and come back year after year without too much effort. However, with some forethought to the soil, attention to the variety you’re planting, and regular pruning, you can maximize the quality and production of your raspberry patch.
Raspberries are one of my favorite berries to eat, fresh or frozen. Although American red raspberries (Rubus idaeus L.) grow wild throughout Alaska, they can be annoyingly small and wormy, although their intense taste does compensate somewhat for these drawbacks. But in my backyard, I’d rather grow larger, more productive cultivars of raspberries.
Raspberries also meet most of my criteria when choosing what to grow. They are a high-dollar item, best fresh, highly perishable, can be eaten without cooking, can be harvested successively, and are something my family will eat as much of as I can grow. As with strawberries, there is much to learn about maximizing production.
Choosing raspberry cultivars to grow
Depending on the region of Alaska you live in and the growing conditions there, consider these important factors when starting a raspberry patch and choosing which variety to grow.
The roots and crowns of raspberry plants are perennial and generally have a lifespan of 10-15 years. However, the canes are biennials. In the first year, the cane is called a primocane; in the second year, it is called a floricane. Raspberries can be divided into two main categories — summer-bearing (floricane-fruiting) or fall-bearing (primocane-fruiting or everbearing).
It’s important to know which type of raspberry you’re growing, how to prune it and ensure that you have a variety that will bear fruit early enough to harvest before the first frost. Nursery descriptions of varieties can be helpful, but they are not specific to Alaska’s growing conditions. What is meant by summer or fall in the Lower 48 can differ greatly from summer and fall in Alaska.
Oregon State University’s publication on Raspberry Cultivars for the Pacific Northwest is a comprehensive and unbiased description of widely available raspberry cultivars. I especially like that they’re listed in order of fruiting. Summer bearers are most commonly grown in Alaska because many fall cultivars will not bear fruit before the first frosts. Season extension or greenhouse techniques could push the season, but I’m not sure it would be worth the trouble, given that many cultivars will bear fruit in time.
In Alaska’s Arctic and Interior regions, cold hardiness is one of the primary considerations when choosing a variety. Consider the cold hardiness of both the crown and the overwintering canes. Many raspberry cultivars are rated as hardy in Zones 3 to 8.
According to the Alaska Garden Helper hardiness zones, Fairbanks may be transitioning from Zone 2b (1980-2009) to Zone 4a (2010-2039), which may expand the varieties we can grow. For summer bearers, the crown and florican need to withstand winter temperatures. For fall bearers, just the crown needs to be winter hardy if they are pruned to the ground each year.
For coastal Alaska, root rot resistance may be a primary consideration, and resistance to other diseases is always a good characteristic to consider.
Size and taste
I’ve eaten some truly tasteless raspberries. Sample different varieties at a local U-pick farm or botanical garden if you can. You may need to ask what variety is being grown, and you will need to ask permission to sample at most botanical gardens. Also, purchase a few varieties before establishing your patch and see which ones you like best and which grow well. If you are experimenting with more than one variety, you need to separate the patches to keep track of what is growing where. If you are experimenting, you can grow them in a container for a couple of years, but you may need to bury the container in the winter to protect the berries from the cold.
Availability is yet another consideration. Some varieties that have been recommended in the past may no longer be widely available. Kiska is an example of a variety that was developed at the University of Alaska Fairbanks in the 1970s but is no longer widely available. Some cultivars are patented, which could limit their availability to home gardeners, increase their price, and disallow you from propagating them. Local greenhouses may have a limited selection.
There are several options to order raspberry plants online. These companies have raspberries and will ship to Alaska: Nourse Farms, One Green World, Raintree Nursery, and Indiana Berry Company Some varieties are patented and can be more expensive than heirloom varieties.
Boyne and Latham are tried-and-true varieties that have been the standbys for Alaska for a long time. They have been recommended by agricultural researchers, Extension, and farmers for years and are available at local greenhouses throughout Alaska. Fallgold is a fall bearer, but also seems to be commonly grown and available from greenhouses throughout Alaska.
Extension recommends Canby for Southcentral in Alaska’s Sustainable Gardening Handbook and by Southcentral Alaska grower, Dwight Bradley, a member of the Alaska Pioneer Fruit Grower’s Association.
Red Mammoth is recommended for Interior Alaska by Extension. It’s not widely available, but I saw it from Food Forest Nursery.
Experimental varieties
I want to try growing Prelude, Nova, and Encore in Fairbanks. Nova is rated down to Zone 3. The other two are rated to Zone 4-8, and with our warmer winters, these cultivars stand a good chance. Prelude is the earliest summer bearer on this list. Who doesn’t want raspberries as soon as possible in the summer? However, these varieties will be experimental as I don’t know of any recommendations or trials for these cultivars in Interior Alaska.
Growing raspberries
Oregon State University Extension’s publication, Growing Raspberries in Your Home Garden, offers in-depth instructions for growing raspberries successfully, including the ideal soil and nutrient requirements, proper spacing, pruning techniques and trellising systems.
They recommend planting raspberries in well-drained soil, with a good layer of organic matter and mulch and a soil pH of 5.6 to 6.5. They recommend fertilizing based on a soil test, and when establishing a new patch, they recommend 2-3 ounces of nitrogen per 10 feet of row per year. When the plants are dormant (late fall or early spring), prune summer bearer floricanes.
Raspberries should be planted 2 to 2.5 feet apart in rows that are 8 to 10 feet apart with a row width of about 6 to 12 inches wide maintained for summer bearers. This width will help you take care of your raspberry patch and limit the spread of disease. Some type of trellis should be used for support, such as t-posts and 12-gauge wires, which work well. I have seen fencing used before, making picking the berries difficult.
Eating and cooking with raspberries
Most of the raspberries we grow are eaten fresh and right away. Any extra, I freeze and eat with granola, blueberries and yogurt. If I were lucky enough to have even more, I would make raspberry scones. My favorite scone of all time is Fire Island’s raspberry scone.
Finally, if I had even more, I would (and do) make raspberry and pomegranate roulade from Yasmin Khan’s cookbook Ripe Figs: Recipes and Stories from the Eastern Mediterranean. If I were fortunate enough to have cloudberries, I would also add them. And if I were blessed with even more raspberries, I would consider making jam or preserving them using UAF Cooperative Extension Services-tested recipes or making yet more yummy things to eat.
Heidi Rader is a professor of Extension and project director for the Alaska Tribes Extension Project. This work is supported by the Federally Recognized Tribes Extension Program Project 2022-41580-37957. It is a partnership with Tanana Chiefs Conference. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.
