A feeding flock of finches is a joy to watch, and I've had much of that joy in recent weeks. I have a nylon mesh sock filled with Nyjer, and while it took a couple of weeks for the birds to discover it, they have done so - with a vengeance. At first is was just a lonely lesser goldfinch or two, but their compatriots quickly joined in. Fast on their tail feathers were the American goldfinches, and shortly thereafter, the pine siskins. Now I have a hearty flock feeding daily, but fortunately, the bin of Nyjer is a generous size and there's plenty for all.
If you want to feed Nyjer to your backyard birds, I strongly recommend a heavyweight sock specially designed to hold these tiny seeds. It may look simple, but a less expensive sock will quickly be shredded under the birds' talons, and a stronger sock not only withstands more abuse, but holds more seed as well. I also have a mesh hoop beneath my feeder to catch spilled seed, and more birds are able to feed there as well - I've had up to 15 or more birds feeding at once, with room for more to join in. I hope more will visit; I've missed these birds in recent months as they've been absent from the new yard, and I'm grateful they're absent no longer.
May you have similar sock-tastic joy in your backyard!