Saffron Crocus can be grown in areas with colder winters than Zone 6, but the corms must be lifted and brought indoors for the winter
. Overwintering corms in cold climates. Harvesting and using saffron.
Store in a cool (40-50°F), dry place. Plant them out again in the spring after all danger of frost has passed, but don’t water until you see new growth in early autumn. Overwintering corms in cold climates.
Another way of growing Saffron Crocus in cold-winter areas like Iran is to plant the corms 2 in. Harvesting and using saffron
deep in clay or plastic pots filled with a well-drained soil mix, and then set the pots directly in the ground, with the rims about 2 inches below the soil surface, so the pots don’t show. After the plants die back in the fall, move the pots into the basement and store them dry for the winter. Overwintering corms in cold climates.
Set the pots back out the following spring.
Again, marking the pots’ location so you don’t accidentally dig into them is probably a good idea. Harvesting and using saffron