This section is from the book "Save It For Winter.", by Frederick Fry Rockwell. Also available from Amazon: Save It For Winter; Modern Methods Of Canning, Dehydrating, Preserving And Storing Vegetables And Fruit For Winter Use, With Comments On The Best ... For Saving, And When And How To Grow Them.
Under this general head are included such vegetables as chard, kale, Chinese cabbage, cress, spinach, cabbage sprouts, beet tops, mustard, and such wild greens as milkweed, cowslips, etc. All of these things are gathered when young and tender and if put up properly make a valuable addition to the winter menu, when vegetables of this kind are especially scarce. One of the first essentials in getting good results with these things is to can them absolutely fresh, the day they are picked, and, if possible, within a few hours after cutting, wash and rinse them until thoroughly clean, and then pick over carefully, discarding old leaves and any tough stems or weeds. The blanching should be done in steam, for 10 to 15 minutes-the latter is not too much. Cold-dip and then cut into convenient length; pack as tightly as possible. Use medium brine or season with salt to taste. A few slips of boiled bacon or chipped beef may be added during the canning to improve the flavor; if olive oil is wanted with the greens, that also may be added at this time. Process as for Beans. Or add 1/4 pint of lemon juice to the gallon of brine, and process as for Green Beans.