It’s spring here in New Zealand which means getting some seedlings ready for planting out for summer crops. For the last few years I’ve raised my seedlings on the kitchen window sill. This works okay, but during September it’s still cold enough here that germination takes ages, especially for heat loving crops like peppers and tomatoes.

The various commercially available options for windowsill greenhouses from the hammer barn aren’t a great fit for my house. This year I finally realised that just chucking the seedling pots into a large zip-lock freezer bag would probable work, and sure enough, it has. Temperatures are higher, and the water is staying in the bag. Germination time dropped from 30+ days to the expected 10–14 for most of the cells.