The Mighty Lingonberry (cont)
By: Robert E. Gough
Lingonberries require little fertilizer. In fact, excessive nitrogen will overstimulate vegetative growth and decrease fruitfulness. It may also interfere with hardening and increase winterkill.
How much is enough? If shoot growth seems vigorous and new shoots grow several inches and remain erect and rigid, fertility is about right. If growth is soft and rampant, with large dark green leaves, you have overfertilized. If shoots are short and the foliage is pale yellow or red during the growing season, plants need some fertilizer. In the North, I make it a rule to apply no fertilizer to fruit plants after the Fourth of July. Most woody plants have completed shoot growth by then, so the fertilizer will do little good. It could, however, stimulate excessive late growth that may not harden in time for winter.
Generally, a small handful of a complete fertilizer, such as 5-10-10, applied in a circle around a mature plant in the early spring, will be sufficient. Use smaller amounts for plants up to about three years old. Fish meal or dried blood are good organic nitrogen sources, but be sure to apply them very early in the spring. Precise amounts depend upon the site and vigor of the plants. If you pay enough attention to them, the plants will always tell you what to do.
Lingonberry, like its cousins, is sensitive to chlorides. Keep de-icing salt, water from chlorinated pools and fertilizers containing potassium chloride away from them.
Propagate plants in spring by splitting and separating a crown and transplanting clumps. It helps older plantings that have become crowded and unproductive. Plunge your spade deep, severing the plant's root system and rhizomes. Lift the plant portion gently and transplant it to another area. That's all there is to it. The only trick is to be sure that you leave part of the rhizome attached to the clump. Without it, the plant will not spread rapidly.
Except for the occasional removal of dead and damaged shoots every spring, lingonberries require no pruning.
Varieties of Lingonberry
Introduced in 1981, this is a very vigorous grower producing exceptional crops of large, light red fruits. It's mild-flavored, in contrast to tart and tangy Koralle.
This Dutch variety is the most popular and provides most European commercial production. Attractive plants are upright and vigorous. The small to medium-sized fruits are highly flavored but somewhat tart. Often fruits of Koralle are blended with those of a more productive but mild-flavored variety such as Sussi.
This recently introduced (1983) Dutch variety produces large, mild-flavored fruits and appears to have resistance to Phytophthora root rot. Fruits ripen one to two weeks earlier than Koralle.
Selected by Dr. Elden Stang from seed collected in Finland, Regal is noted for its superior fruit size and early bearing.
This new Norwegian introduction produces some fruit but is mostly noted for producing abundant pollen, which makes it a valuable pollinator.
This Swedish variety is slow to establish but ultimately produces large red fruits abundantly.