Tips for buying, prepping, dehydrating, & freezing leafy greens

It’s no secret that we all should be eating more leafy greens — they’re one of the most nutrient-dense food groups on the planet. This guide has what you need to know about buying, prepping, dehydrating, and freezing leafy greens.

Greens can seem a bit intimidating, especially the large-leafed greens like kale, collards, chard, escarole, and mustard greens. Spinach, arugula, watercress, and tender Asian greens are a bit easier to handle, but even those can benefit from a few tips. Let’s dive right in …

Why you should be eating more leafy greens

Greens are the most nutrient-rich vegetable group, with a multitude of benefits.The hardier greens, like kale, chard, and collards, are superb sources of highly absorbable calcium, a perk that’s especially valuable to those on plant-based diets.

They’re one of the best sources of Vitamin K, essential to bone health, and are abundant in vitamins A, B (especially folic acid) and C. Greens also provide a wealth of antioxidants and chlorophyll, are protective against cancers, and are anti-inflammatory.

All of these are great reasons to eat more greens, aside from the fact that they’re delicious, versatile, and add interest to all manner of preparations. Here are some basic tops to help you enjoy them every day.

Arugula

Buying leafy greens

The more delicate the greens, the more perishable they are, so its best to buy them with the intention of using them within a couple of days. Choose greens with firm, uniform-colored leaves, with few if any wilted or discolored ones.

Make sure to take advantage of farm markets for just-harvested greens in season!

Hardier greens like kale, collards, mustard greens, escarole and chard keep well for several days in the refrigerator, but the sooner you use them after they’ve been harvested, the more nutrients will be intact, and the better their flavor will be. Wrap any variety of hardy greens in paper towel to absorb any extra moisture, then in a tightly sealed plastic bag and refrigerate until using.

Edible greens that come with their vegetables (radish, turnip, beet, etc.), the same rules apply. Often I find that these greens have seen their better day, since the vegetables they’re attached to are much longer-lasting.

If you spot a leaves still fresh and unblemished attached to their bunch of vegetables, make sure to use them up quickly, or use one of the freezing methods in that section.

Collard greens

Stemming and chopping greens

To use stems, or not? That’s a matter of personal preference for each cook to decide.

Small greens like baby spinach, arugula, and most tender Asian greens like tatsoi and mizen need not be stemmed at all.

Mustard greens and escarole midribs are tender and can just be chopped or sliced along with the leaf.

Stems of larger spinach and arugula leaves tend to be stringy and I like to remove them, though others may not find them bothersome.

Chard stems are celery-like, so it’s good to use them. Rainbow chard stems look especially nice in most dishes. It’s best to cut or tear the leaves away from the stems, then slice the stems very thinly. Then, the stemmed chard leaves sliced into rough ribbons or chopped into bite-sized pieces.

Take or leave kale stems. I don’t find they add or detract much from any preparation, so whether they end up in the finished dish or in the compost is largely a matter of preference. In either case, cut the leaves away from the stems. if using them, slice very thinly and cook at the same time as the leaves. If not, compost or discard.

It’s easier to cut flat leaves like lacinato kale into ribbons, and fairly pointless to try to do so with curly kale, which bounces all over the place while it’s being cut, so simply cut the latter into bite-sized pieces.

Collard green stems are too bitter and tough for my taste, so off to the compost they go. My favorite way to cut collard leaves is to stack 6 or so similar-size halves of leaves, roll them up snugly from one of the narrow ends, then slice thinly.

Once they’re nicely cut into these long, narrow ribbons, cut in the opposite direction to shorten. This method of cutting collards is now preferable to the older one of boiling the whole leaves for 15 to 20 minutes before chopping.

Rainbow chard

Rinsing leafy greens

Green leafy vegetables grow close to sandy soil, which tends to cling to the leaves. Nothing ruins a good dish like a mouthful of sand, so do wash leaves very carefully.

Greens bought from the supermarket tend to look much cleaner than ones you’d get from a farm market or CSA, but don’t skip the step of giving them a good rinse even if they’re organic and look perfectly clean. You just never know.

If the greens look fairly clean, like baby spinach, chard, and collard greens from the supermarket, a good rinse in a colander will suffice.

Greens that have more savoyed (the fancy way to say “crinkled”) leaves and for domestic and Asian greens bought at grocery or farm markets need closer attention. Chop and stem them first if need be (see section above), then immerse in a big bowl of cold water.

Swish the greens around with your hands, then let them stand for a couple of minutes. Scoop them out, discard the water, and repeat until the water looks perfectly clean. Even after doing this, it doesn’t hurt to give the greens one final rinse in a colander.

Green and purple baby kale

How to freeze leafy greens

These methods are outlined here for anyone who has a garden that bears greens overabundantly, or who belongs to a CSA that offers more greens in a weekly share than you can possibly use.

Freezing works well for most greens, especially the hardier ones. Watercress doesn’t freeze well, and it’s not the ideal treatment for delicate Asian greens.

Blanching is the more traditional method of freezing greens; here are the basic steps:

Stem, chop, and wash greens very well (see preceding section on stemming and chopping). Bring a pot of water to a boil (the pot should be large enough to accommodate the greens comfortably).
Prepare a large bowl of very cold water.
Immerse greens into water quickly, once it’s at a boil. Cook briefly, depending on the type of green (30 seconds or so for tender greens like spinach and arugula; 2 to 3 minutes for collard greens; and anywhere in between for kale, chard, mustard greens, broccoli rabe, and Asian greens), just until bright green and barely tender.
Drain the greens and plunge them into the cold water to stop the cooking process. Drain well again.
Pack the greens into small containers, with as little air as possible; or into freezer bags, pushing out excess air. If you’d like, affix a label with the date the greens were prepared, and freeze at once.

Stir-fry method for freezing: A more contemporary method is to stir-fry clean, chopped greens using as little oil as possible (you can add chopped garlic), until tender-crisp. Let the greens cool, uncovered, then pack and freeze as in step 5, above. When ready to use, allow the greens to thaw in the refrigerator, or thaw partially and add to stews or soups to completely thaw. Frozen greens are best used within 6 months of preparation.

Pesto for freezing: This is another excellent method for compacting down a good quantity of leafy greens. Spinach, arugula, and kale are all excellent candidates for leafy greens pesto. Once ready, you can portion the pesto into small airtight containers, where it will keep well in the freezer for up to six months.

Some cooks like to put pesto into ice cube trays so you can pop out a small cube or two when need. The issue here is that you need to find a way to cover the tray so that the pesto won’t get freezer burn or lose freshness.

Here are some recipes on this site for pesto, or that contain a sub-recipe for leafy greens pesto:

Baby kale

How to dehydrate leafy greens

Truthfully, I don’t find dehydration the best method for preserving greens. My experiments with reducing juicy greens to dried chips with the idea of rehydrating them at some point seemed like too much work for the result.

An average-size dehydrator can hold just so much, so drying a big batch of greens can be a huge undertaking. And because the leaves furl this way and that, this method doesn’t even offer the space-saving advantage that freezing does.

However, dehydrating does offer an alternative to making small batches of green chips, instead of in the oven. The slow-drying helps the leaves dry more evenly than they do in the oven.

The best greens to use for this method are curly kale and collard greens. Baby spinach works well, too, and needs little preparation.

Cut clean kale or collard leaves into bite-size pieces (or use whole baby kale leaves) Make sure they’re already dry before putting them into a dehydrator. You can toss them with a little oil and salt, and for added flavor, experiment with your favorite spices as well as some nutritional yeast.
Each dehydrator is a little different, but as a starting point, try drying baby spinach at 110º F. for 6 to 8 hours; kale and collards at 130º F. for 8 to 10 hours.
Once the leaves feel dry and crispy, dehydrate for yet a little longer. The greens don’t stay nice and crisp unless they’re really and truly dried.

It’s best to eat these dried kale or collard chips as soon as they’re ready, as they taste best fresh from the dehydrator. The crisp greens do absorb moisture from the air and become less crisp the longer they stand.

If you don’t finish this addictive snack at once, store any dried green chips in an airtight container—and use them as soon as possible, as they are still, for all intents, fresh veggies. During warm months, store them in the refrigerator.

Explore more about Leafy Greens

More sources

These sources were helpful in the researching Wild About Greens (2012), from which the information above was adapted.

Andrus, Becki. “How to Dehydrate Kale.” Ezine Articles. 2010. 30 Nov. 2010.
Bucks, Buster. “How to Preserve your Garden Harvest: Freezing your greens.” Hub Pages. 13 Jan. 2011
“Freezing Beet Greens.” Doris and Jilly Cook. Adventures in Growing, Making, Preserving and Eating Foods. 28 July 2009. 19 Nov. 2010
“Freezing Greens.” Michigan State University Extension: Preserving Food Safely. 3 July, 1999, 30 Nov. 2010
“Freezing Spinach.” Thrifty Fun. 22 July 2006. 16 Nov. 2010
“Freezing the Spring Greens.” Rooting Down: Putting the Culture Back into Agriculture. 7 April 2009. 16 Nov. 2010
“Freezing Turnip Greens”. Doris and Jilly Cook. Adventures in Growing, Making, Preserving and Eating Foods. 28 July 2009. 19 Nov. 2010
“How to Blanch and Freeze Kale.” Not Martha. 12 June 2009. 30 Nov. 2010
“How to Dehydrate Kale.” Ezine Articles. 2010. 30 Nov. 2010.
“How to Dehydrate Your Greens.” Chile Chews. 26 March 2009. 11 Jan. 2011
Potts, Jennifer L. “How to Freeze Bok Choy.” eHow. 2011. 14 Jan. 2011
Williams, Allens. “Dried Bok Choy Offers Nutrition and Intense Flavors.” Suite101.com. 16 Nov. 2009