I have one standard treatment for all these sturdy, leafy greens. Dump them all into a sink full of cold water. Especially in hot weather, rehydrating the leafy greens will extend their life by days. You need enough water that the leaves float and the dirt sinks. Swish things around, then let them sit so the dirt settles. Scoop the leaves off the top and wrap them in a dish towel or paper towels and then maybe put all that into a plastic bag. Leave the bag open so moisture can escape. If you can make the time, it’s really best to go ahead and prep the leaves the way you’ll want them for your recipes. Strip leaves off stems, for example, maybe chop the leaves. Just remember that the smaller the bit of green you’re storing, the shorter the time it will keep. So chopped kale – a day or two. Whole kale leaves? Weeks. (Although weeks means the leaves get more and more wilted.)
We do receive enough greens that you may want to freeze them for using over the winter when there’s no weekly Riverview box. Best to do the traditional blanching. Prep the leaves in the form you’re most likely to use for cooking, put them into boiling water until they just turn color, then put them into a bowl of ice water to quickly cool. Drain them, squeeze out excess moisture and place in freezer storage containers.