If you can not make it through a hearty bunch of collard greens before they are past their prime, you can preserve their goodness for use later by blanching and freezing them. Take it a step further and save those stems for making a nutritious easy homemade stock base.
Freeze
Make Stock
Cook fibrous stems in water with a whole quartered onion, couple carrots and celery stalks, a few whole cloves of garlic and some black peppercorns for 45 minutes. Use stock for soups, stews and braising recipes.