?60 days. The Swiss Chard Fordhook Giant is a variety that can grow to be over two feet tall. This plant produced broad, dark green leaves with bright white stems which are 2 ½" thick. Leaves can grow quite large, 24 to 28 inches in length, and are heavily crumpled. This variety is excellent for gardeners looking to produce mass amounts of high quality Swiss chard with the purpose of eating, as Swiss chard with white stems is high quality in both texture and flavor. This crop grows well in zones 6 and higher. After around 60 days, each stem can be harvested individually, and harvested throughout the summer. Leaves are wonderfully tender and juicy!?