Nesting Hummingbirds

Does anyone know what Hummingbirds build their nests out of around here? I have a female Black-Chinned that has nested somewhere in or near my yard the past two summers. I would like to make sure she has nesting materials and maybe attract some more. I saw her gathering spiderwebs at the end of July about the same time the Cottonwood cotton was flying, so that might be what her 2nd nest was made out of. I want to know what birds use earlier, in about May. I have read they use cinnamon ferns, but they aren't native around here and obviously our birds have got by without them. Any ideas? Thanks

My AB bird book says the ruby throated and rufus use moss, bark and lichen to build their nests here.