Collard greens grow well in many parts of the world. They are robust, beautiful and prolific plants. They do not have to be cooked for an hour with a ham hock (though by all means do if you can). There are many quick and fresh preparations for these delicious greens. You can even use tender, young leaves raw as in the salad with apples and walnuts.
I do sometimes blanch collards greens in lightly salted boiling water for 5 minutes and then proceed to use them in other recipes or as is. If you’re afraid you won’t get to them before they start yellowing you can blanch and then take your time in using them as they’ll keep 3-4 more days once cooked.
Collards keep well in a plastic bag in the refrigerator for 3-7 days or so depending on how fresh they are to begin with.