So I planted them in shallow pots. And they are doing great, as you can see. Only problem is, they are frost tender and I dare not plant them out for another month. Case in point: frost is predicted for tonight. So, I’m thinking I need to pot them on, but what size pot should I use? Shallow or deep? And should I pinch the stems? Cold climate gardeners, I need all your dahlia tricks and tips!
Dahlias have never done well for me. Yes, they grow. But they usually bloom for the first time about three days before the first frost. Every couple of years I try to find a warmer microclimate than the last place I tried. I’ve never gotten much bloom no matter where they’re planted. So I figured it was time to give them a head start, just like we have to do for all the frost tender vegetables and annuals. But I find I really don’t know dahlia physiology; I don’t know if their roots go deep or wide. So help me out here!