Hardy elderberry bushes thrive in most climates, tolerating both summer heat and winter freezing. The bushes grow reliably to USDA zone 4, and some elderberry varieties can survive in zone 3. Hot weather and direct sunlight can scorch the bushes in summer. Planting in a location that receives afternoon shade, such as under deciduous trees, protects the bushes. Avoid crowded areas or sites with poor air circulation, as lack of air movement can lead to fungal problems on the bushes.
A high organic matter content creates moist but well-drained soil---optimum conditions for elderberry growth. The bushes thrive in mildly acidic soils with a pH between 5.5 and 6.5. Adding organic matter to the bed prior to planting, using compost or composted manure, improves the organic matter and moisture retaining ability of the soil. Elderberries also require annual spring fertilization to replace the nutrients in the bed. A balanced, 10-10-10 fertilizer provides sufficient nutrition. Supply a 1/2 lb. of fertilizer per plant for each year of the plant's age, up to a total of 4 lbs. per plant.
Elderberries have a shallow root system so they do not seek deeply into the soil for moisture. The shrubs require regular weekly watering, or at least 1 inch of irrigation, to obtain the moisture necessary for healthy growth. Mulch around the elderberry bushes with straw or another organic mulch to help keep the moisture in the soil. The shrubs also can't tolerate weed competition, as the weeds rob moisture from the bushes. Weeding around the base of the elderberries regularly improves the health of the bushes.
Regular pruning keeps the bushes healthy, attractive and productive. Elderberries produce fruit primarily on 2-year-old canes. The plants require pruning in later winter, before they begin putting on new growth. Cut out any canes or stems that are more than 3 years old, as these no longer produce fruit. Also remove any dead or damaged canes, cutting them off at the base. If the bush is overgrown and becoming crowded, remove some younger canes but leave at least three each of 1-, 2- and 3-year old canes to ensure good berry production.