This spring, I planted some dinosaur kale. It;s growing o.k. but has some problems. All the leaves began to have holes in them. I thought it might be snails or slugs , so I put out some Sluggo to kill the slugs.. I checked the leaves- top and underside- to check for worms or white flies---couldn't see anything there, but continued to see leaves eaten up. My son said that he saw many little birds sitting on the plants eating the leaves. He thought the birds might be finches, but not sure. I've never heard of such a thing. Do birds eat kale leaves? What should I do to save my plants ? They've already killed 2 plants.
Some birds do indeed feast on greens, which undoubtedly provides nutrient to their diet just as greens are good for humans. The birds most likely to have been on your kale are Lesser and/or American Goldfinches. You need to protect your kale with bird netting, preferably stretched over hoops to make a tunnel- like covering. Most farm and garden supply stores, as well as some of the big-box home improvement stores will carry what you need: bird netting of a size to stretch from end to end plus 2 times the height of the support (there are 2 end openings you'll want to cover) of your kale patch, as well as wide enough to stretch over the width plus height of your patch. Both wire and plastic hoops can be used to support the fabric. One of the least expensive materials for hoops is 1/4 inch diameter PVC pipe. The pipe can be supported by rebar pieces about 12" long driven into the ground on each side of the patch , about 2 feet apart, onto which the ends of the PVC pipe "hoop" will fit. If you are gardening in a raised wooden bed, you can use plumber's pipe clamps to secure the PVC hoops to each side of the box. You can also shop the various garden supply companies on the web who almost always have "tunnels" of various lengths and widths available. These are usually wire hoop structures sewn into a cover of what is known as floating row cover, lightweight non-women polyester cloth; some tunnels are available with mesh or netting. Floating row covers are useful all year round. Kale is usually a fall-planted crop which tolerates light frosts and actually "sweetens up" after frost. Kale and other winter greens can be protected from severe frost by floating row cover "tunnels" made of heavier material. Enjoy the fruits of your labors!