When to plant brussels sprouts in zone 6a
In zone 6a, the average last spring frost is Apr 28 and the first fall frost is Oct 15. Here is brussels sprouts's whole year, counted from those dates.
Grow them in fertile, well-drained soil that still holds moisture, with a pH of 6 to 7. They are a long, cool-season crop. Hot, dry weather at maturity makes loose or bitter sprouts. Keep the bed watered through summer heat.
Maryland says to set 4–6 week old transplants in the garden 90–100 days before the first fall frost, and to add about 20 days if you direct-sow instead. This calendar follows the transplant path. The outdoor date is the middle of that 90–100 day range, and the indoor date is five weeks earlier, the middle of the 4–6 week transplant age. Sow seed ¼–½ inch deep. Direct-seeded plants can take as much as three more weeks than transplants.
Space plants 18–24 inches in the row. Illinois also calls fall production the practical crop in most of the country and says to allow at least 90–100 days before the first frost. A published spring transplant schedule was not used here. Top the plant when the lowest sprouts are about ½–1 inch across so the upper sprouts size up.
Days to maturity are 80–100 from transplanting, which is Maryland's maturity range and not the same figure as the 90–100 day lead time before frost. Pick hard, compact, deep green sprouts about 1–1½ inches across. The lowest sprouts mature first. Flavor is best after frosty weather. A week count for how long picking continues was not published in the guides used here.