I live Edmonton, Alberta,Canada. I bought marigolds recently and planted them outside in the lawn, in weekend when the temperature was 20-23 degrees Celsius. Suddenly during the week the temperatures dropped to 0 and -1 celcius and it snowed. I tried to protect the plants by covering it with mulch. The plants at first seemed okay but slightly bent so tied them to a stick for support. Today they completely wilted. Is there anything I can do to save them? Thank you so much for your help
The green parts of that plant are dead. Only time will tell if the roots have enough energy reserves to regrow, but it's not likely. A perennial that has its top killed by frost may regrow from the roots, but annuals usually don't have the stored reserves to allow regrowth.
I would leave the top until it dries out, then remove it by breaking or trimming it off at the soil level. Then re-plant new annuals between the spots where you planted the old ones. That way, you leave the marigold roots intact, so just in case they still have some life in them, they'll have the chance to regrow.
Spring gardening can be a real heartbreaker. Better luck with your next planting.
