Although they are hardy to Zone 2, lingonberries are susceptible to winter injury. In areas with poor snow cover or severe cold before snowfall, blanket the plants with a five- to seven-centimetre-thick layer of mulch (straw, hay or dead leaves) once the ground surface has lightly frozen but before extremely cold weather has set in.
In spring when the risk of frost has passed, remove the winter mulch, pull back the permanent mulch of sawdust or wood chips and spread compost around each plant. Fertilize lightly with a balanced acidic fertilizer, such as that used for azaleas and rhododendrons. Be careful not to damage the fibrous surface roots, either by touch or by over-fertilizing; use the recommended rates. Replace the mulch, adding more if necessary. Once the plants begin to leaf out, remove any dead branches or twigs. This is the only pruning the plants require.
Lingonberries spread by forming a mat of above-ground stolons and underground rhizomes, which produce more plants. If the shrubs become overcrowded, or you want to start a new patch, use a sharp shovel to dig up a well-rooted clump in early spring or fall. Plant these in the same way as the original ones, watering them in well and providing mulch. Irrigate regularly until they are fully established, keeping the soil moist but not soggy.
The time it takes lingonberries to flower and fruit varies. Some fruit one year after planting, while others grow slowly for two or three years before producing berries. Once established, they will yield two crops if the season is long enough: one in mid-August and a second, often more plentiful crop in mid-October. However, named varieties usually have heavier and more reliable crops. Harvest when the berries are fully red; pick by hand or use a berry rake for large quantities. If damaged fruit is discarded, lingonberries will keep in the refrigerator for several weeks. Store them unwashed in a sealed container.
Lingonberries can be eaten raw, cooked or processed. Add their juice to cranberry or other fruit juices, or combine with rosehips to make a tasty jelly. Lingonberries can be processed for sauces, jellies, syrups, preserves, candy, drinks, pickles and wine, and can be added to pancake batter, ice cream and other dairy products. They also make a great substitute for cranberries in recipes.