In 2011, we established a small planting depth trial to determine optimum conditions for establishing the new haskap fruit crop developed by the University of Saskatchewan – Saskatoon fruit program www.fruit.usask.ca .  Haskaps from the breeding program were first released to the public in 2007.

The planting trial is small.  It includes eight plants each of ‘Tundra’ and ‘Borealis’.  In 2011, half of each of these (4 plants) were planted 1-inch deeper than the nursery plant and half were planted 3-inches deeper.  The following spring, half of the plants were pruned to several buds to promote branching.  In the following years, plants were pruned with standard practices.

The first fruit from this trial was harvested in 2014 under good fruiting conditions.  2015 fruit developed after poor pollinating conditions and the crop was small. The conclusions were the same in 2014 as were observed in 2015. Results for ‘Borealis’ and ‘Tundra’ were as follows:

• ‘Borealis’ had less fruit if it was pruned and less fruit when planted 1-inch deep.
• ‘Tundra’ had less fruit if it was not pruned and less fruit when planted 3-inches deep.

Assumptions from Haskap Planting Depth Trial of ‘Borealis’ and ‘Tundra’:

• ‘Borealis’ is a naturally well-branched plant.  Pruning delayed its branching pattern.
• ‘Borealis’ prefers to be planted deeper.
• ‘Tundra’ is a rangy, thin plant when young.  Pruning will increase its branching habit.
• ‘Tundra’ prefers to be planted less deeply.

In the future, I would:

• Plant ‘Borealis’ (2”pots) 3-inches deeper than it was situated at the nursery and I would not prune it back severely the next spring.
• Plant ‘Tundra’ (2”pots) 1-inch deeper than it was situated at the nursery and I would prune it back to several buds to increase branching in the future.

The University of Saskatchewan continues to make thousands of haskap crosses each year. Four varieties have been released since this original breeding and dozens more come into the US from Europe and Japan.  Dr. Maxine Thompson, of Oregon, has given rights for a few plants to several propagation companies in the US, as well.  Look for the Proven Winners varieties named ‘Solo’ and ‘Maxi’ as well as others to come.

The message to take away is that haskap and honeyberry production knowledge is in its infancy, especially here in the US.  I hope that commercial growers in Canada are doing a bit of experimenting as they go along.

Kathy Wiederholt

Fruit Project Manager