[coronabarb]

You can freeze them - for best quality, blanch for 2 mins. You can also dehydrate them. I dried the leaves of brussel sprouts plants, then ground to powder and add to casseroles, soups, etc. Yes to fermenting like sauerkraut or kimchee. Look for a recipe with lots of salt since that is what inhibits bad bacteria. To can greens, you would have to pressure can them since they are low in acid.