21-35 days.   A beautiful mizuna (Japanese mustard).  Leaves of reddish-purple will look great in any salad.  With a mild taste and lovely color you'll want to use it all season long.  Can even be planted in containers to keep it close to the kitchen.
                                        
                    
            
Growing Zone: 3 to 9
          
                              
            
Light Requirements: Full Sun          
                                        
            
Height: 8 in