84-91 days. Rainbow Mix coleus seeds are a unique grow for many gardens prone to heat across the country. Rainbow Mix seeds grow dwarfed 12-15" tall coleus shrubs in a spectacular mix of tropical magentas, greens, yellows, and reds. Coleus seeds blend well with lavenders, plectranthus, and other similar blooms and are sure to dazzle all the way up to the frost. Rainbow Mix coleus seeds are an efficient and brilliant way to reinvigorate commercial properties and real estate. 1000 seeds.