Seed from rainbow chard we've let run wild for a few generations in our garden.
 
Germination Temperature: 5℃ - 38℃ / 41℉ - 100℉
Minimum and Maximum Temperature: -9℃ - 36℃ / 16℉ - 96℉
Ideal Growing Temperature: 10℃ - 17℃ / 50℉ - 62℉
Days to Maturity: 50 - 70 days / Maximum life of 2 years