Elderberry bushes (sambucus spp.) are fruit-bearing shrubs that are extremely cold-hardy. Elderberries can be grown in cold-winter regions, down to USDA hardiness zones 3 or 4, tolerating winter temperatures as cold as -35 degrees F. Elderberry shrubs bloom in flat-topped clusters of tiny white flowers in late June, followed by a crop of berries containing dark purple juice in late summer or early autumn. Elderberries must be cooked to be edible, because the raw berries are astringent.
Choose a planting site for your elderberry bushes that's in full sunlight and has rich, moist, well-draining soil. Elderberries prefer a soil pH of 5.5 to 6.5.
Plant your elderberry bushes in spring, after all chances of frost have passed. Dig planting holes that are the same depth as and twice the width of the nursery containers, spacing the elderberry shrubs 6 to 10 feet apart.
Remove the elderberry shrub from the nursery container and set the roots into the planting hole, planting the shrub at the same depth as it was in the container. Backfill the planting holes with the displaced soil and water the soil deeply and thoroughly.
Water your elderberry shrubs thoroughly once or twice per week to supplement rainfall during the first growing season after planting them. Soak the soil around the entire root area of the shrubs. After the first year, water the elderberries once each week during the spring, summer and early autumn only in the absence of rainfall.
Feed your elderberry shrubs once each year in early spring with 1/8 pound of ammonium nitrate or ½ pound of 10-10-10 NPK fertilizer for each year of the shrub's age. Elderberry shrubs that are 8 years old or older should receive no more than 1 pound per plant of ammonium nitrate or 4 pounds of 10-10-10 NPK fertilizer.
Prune your elderberry shrubs once each year in late winter or early spring to remove all canes that are more than three years old. Prune away all dead, weak or damaged canes. Try to leave equal numbers of 1-, 2- and 3-year-old canes on the elderberry shrub.
Harvest the elderberries from late August until early September when the fruits achieve their mature color. Remove the entire fruit cluster when harvesting the elderberries.