Anybody got an idea what's going on with my broccoli seedlings?
They've all grown about an inch high, but now about five of them have suddenly keeled over. Upon examination, the little stems seem to have withered right at the soil (actually organic starter mix) line or slightly above.
I've never had this happen before. The seedlings are in starter trays, under full-spectrum lights, on a heat mat, and have had adequate moisture.
Have any of you gardeners had this happen to any of your seedlings? And do you know what's caused it?
Thanks for any help or suggestions you may have.