By Mark Wolbers
In the summer of 2010, I planted a test plot of arctic raspberries (Rubus arcticus L. subsp.x stellarcticus) also known as nagoonberries. I ordered three cultivated varieties developed in a Swedish breeding program to assess vigor, flowers, fruit size and production. The varieties tested are sold under the names Beta, Sophia, and Valentina. It is recommended to plant more than one variety.
All three were planted in an 8 x 2 foot raised grow box with garden soil. The growing conditions and media were identical for all three varieties. The soil was very fertile – perhaps too fertile. Fruits near the soil were susceptible to molding. If planted as a ground cover, it might help to put down a layer of wood chips or straw to help keep any fruit away from ground contact.
The amount and size of fruit, even on the best plant, was small in comparison to a regular raspberry. Despite its small size, I found the fruit extremely aromatic, sweet and tasty. However, unlike a raspberry, the fruit does not release cleanly from the stem.
The plants that had arrived in 2010 in 3” pots had expanded to approximately 12” one year later (2011). By the beginning of the second year (2012), the plants had completely filled the 2 x 8 box! However, I needed the box for growing purple raspberries, so I dug out all of the nagoonberries. These were shared with APFGA club members at an early summer meeting at Clark’s orchard.
Since there was a problem with fruit contacting the soil and molding prematurely, I decided to try planting them in a narrow (6”) box where the foliage, flowers and fruit could hang over the edge.
I also used less fertile soil and they did not seem to mind that either. The 6” x 48” box was planted with a divider down the center with one half Valentine and the other half Beta. By minimizing ground contact, the fruit maintained better quality. But perhaps the most striking outcome was how beautiful the boxes were in the spring and fall. Nice flowers in the spring and very colorful and attractive foliage in the fall.
These plants are vigorous runners, and since my box was on the ground, the plants escaped through the cracks of the cedar boards. So, this past year, I elevated the box off the ground. This produced the best results. Not only were the runners thwarted, but I suspect that the slightly drier environment by being off the ground helped the overall fruit quality.
In summary, if you are considering these plants, do not plan on high fruit production. Standard raspberries produce much more fruit. Also, beware that they are a ground cover and will run aggressively (warning!). They are difficult to eradicate should you decide you don’t want them. However, nagoonberries are extremely hardy and do provide attractive flowers and beautiful fall foliage. In addition, nagoonberries have a flavor and aroma that is unique in the “Rubus” family.