When you get home, unbundle your herbs, wash immediately, and shake off excess water.
If you’re storing cilantro/coriander: Cut the bottoms so you have a fresh edge on all stems. Fill a glass with an inch or two of water. The glass should be large enough to hold the stems comfortably, don’t pack it in. Place the stems in the glass, and then place a plastic bag over the top to create a little “dome” over the leaves. I tend to use a quart bag, but you might need a bigger one depending on how long the stems are. Be sure to replace the water every once in a while.
For pretty much any other herb as far as I can tell: Lightly wrap the herbs in a slightly damp paper towel, then place in a large, open ziptop bag. Every once in a while, replace the damp paper towel or redampen it if it feels dry.
Finally figured out how to keep cut herbs fresh in the fridge for more than a few days. No more green slime. 👍
Cilantro, parsley, thyme, sage, and rosemary have all done well in my fridge with this technique. The cilantro has lasted weeks, which is shocking.
Mint did really well too, but I feel it might last slightly longer if treated like cilantro. Will experiment.