I often can’t use greens fast enough to keep them from wilting, but I hate throwing them out! At some point, I realized that blanched greens can be frozen, but a whole pound is too much to use at once. Then B. found this giant silicone ice cube tray and I found the solution.
I chop the chard (or kale or whatever) into useable pieces, wash it and boil for 2-4 minutes to blanch. Then I drain it (reserving some of the liquid if I can) and pack the greens into the ice cube tray. A pound of greens fits nicely into one tray. I fill the interstitial space with water (like the reserved water if you caught it, or fresh water if you didn’t) so that it freezes into a solid block. When you want to use it, just drop it into soup or a sauté or even smoothies. (Kale is almost undetectable in berry smoothies)