- A mix of red, orange, yellow, and white stemmed Swiss Chard that is slow to bolt.
60 days. The Rainbow Mixture Swiss Chard seed mix is a blend of different colored swiss chard varieties. The chard can grow in zones 6 and up, and the leaves can be harvested after around sixty days. The Rainbow Mixture Swiss Chard leaves have a bitter taste, similar to that of spinach. Our own blend of colored swiss chards includes red, yellow, orange, white, and vivid pink stems that merge into dark green savoyed leaves. The rainbow heads are slow to bolt and quite lovely in bunches. This variety is ornamental/edible landscaping at its best.