They're going for the seeds, of course, and they seem to prefer them still on the plant. In the absence of seed trees like birch, alder, and elm or grasses, thistles, and other weeds that provide seeds, your zinnias are right up their alley. Cone flowers and Black eyed Susans would probably tempt them too. I don't usually feed birds in the summer, but how about erecting a temporary feeder stocked with their preferred seed?

Echinacea is a rampant reseeder in my garden. So much so, that I have gotten much more ruthless about weeding out the seedlings. This didn't happen right away, but after a couple years the Echinacea plants seemed to mature and start seeding all over the place. I always never deadhead the Echinacea, because the Goldfinches love to eat the seed. In the fall, I sometimes collect dried seedheads, store them in garage, and tape them up to the bird feeder pole, and the Goldfinches will eat them over the winter. Even so, plenty of seed manages to drop to the ground and sprout. If you want to encourage seedlings, then don't deadhead, don't use Preen, and don't mulch heavily. It is also easy to collect the seed and start your own plants.

If you look at a detailed zone map, you'll see along the coast it swoops way up here. I am a mile from the intracoastal, so I think that's the appropriate zone for me. I'm not sure other birds eat the thistle, I would think so, seems unlikely only Goldfinches would. Last year I was getting around 2 dozen or so goldfinches, with no socks, only sunflower seed and millet. Later today the goldfinches came back a couple more times, so I hope they are regulars for the season. I love their funny sounds they make. Gary

Wow, this thread is still going! I finally beat the squirrels; I had winter sown a few sunflowers. While they were growing taller and taller every day, I was afraid to plant them in the ground; I knew the squirrels would get them. I cut up a piece of green wire fencing, creating a cage, about 3' tall. They're awesome!!!!! One came from my birdseed; I transplanted it and it grew to about 5', with a huge head. I also grew "Russian Giant" and "Lemon Queen"; they're huge. The house finches returned and always seem to chase the goldfinches away, but they're flocking to the plants; I love it! Agastache "Honey Bee Blue" Echinacea Rudbeckia Oenothera biennis Sunflowers Tithonia "Sundance" I even saw one pecking on my buddleia today. DH saw a few on the Agastache a few weeks ago; even he was impressed.