Nova
Elderberry in the US

You won't often find elderberry plug plants, so you're usually starting from seed or planting a young bare-root plant. If you're sowing seeds, timing really depends on your USDA zone, like the GrowMore CookMore app shows for zones 5-7. For many, that means starting seeds indoors in March or April, or even in fall for some zones, to let them stratify over winter. Plant seeds about a quarter-inch deep (6 mm) in good potting mix, then keep them moist. If you're planting a young plant, do it after all danger of frost has passed in your area.

Once your elderberry seedlings are big enough to handle, prick them out into individual pots. Harden them off gradually for a week or two before planting them outside. You want to make sure the last frost has well and truly passed before they go into their permanent spot. Give them plenty of room, about 6 to 10 feet (1.8 to 3 meters) apart, as they grow into decent-sized shrubs. They'll appreciate a sunny spot with good drainage.