Wow! That’s great that you were able to get another harvest a second year! Brussels sprouts are biennials, so they will normally only last 2 years, and will want to flower the second year. The plants like cold weather, and the taste of the sprouts improves after a few frosts, but the plants may not survive much past a series of killing frosts, into the first part of winter, depending on climate. I’m not sure how long the plants will last now that they are 1-1/2 years old, but before the first hard, killing frost is expected, you might protect the plants by covering the stems with mulch, such as straw or leaves; also apply a thick layer of mulch over the soil, to help protect the roots. Some gardeners dig up the plants, roots and all, and store or replant indoors to prolong the harvest a month or so. Good luck!
Wow! That’s great that you were able to get another harvest a second year! Brussels sprouts are biennials, so they will normally only last 2 years, and will want to flower the second year. The plants like cold weather, and the taste of the sprouts improves after a few frosts, but the plants may not survive much past a series of killing frosts, into the first part of winter, depending on climate. I’m not sure how long the plants will last now that they are 1-1/2 years old, but before the first hard, killing frost is expected, you might protect the plants by covering the stems with mulch, such as straw or leaves; also apply a thick layer of mulch over the soil, to help protect the roots. Some gardeners dig up the plants, roots and all, and store or replant indoors to prolong the harvest a month or so. Good luck!