It's one thing for a gardener to provide annuals and perennials that will feed visiting birds all season, whether from the plant itself or the bugs that the plant attracts.
But here's another idea: Grow plants from which you harvest seeds to feed birds.
Venelin Dimitrov, a buyer/product manager of flower seeds at Burpee Seeds and Plants, says the first thing to do is determine which birds are in your area, then identify the plants that will attract them.
To produce a year-round seed supply, you would need a good chunk of land -- a quarter-acre, said Dimitrov. But even a few dozen of these plants can supplement other seeds after the growing season.
Birders may have heard that red millet, a common ingredient in commercial birdseed, has little nutritional value. That shouldn't rule millet out, Dimitrov said.
"Some [millets], because of the hard shell, they're good for their digestion," he said. "They don't have a stomach like ours, based on acids and enzymes. It's based on muscles. The gizzard is like a mill that grinds seed. ... Sometimes it's recommended [they] have a good source of grit, like a sand, [that they] use in their little stomachs to grind seed."
If you decide to go with a millet, he suggests Purple Majesty (Pennisetum glaucum), "a really pretty plant, and it produces a nice seed head that can be dried out and used in the winter."
If there's a trick to making your own birdseed, it's knowing when to collect the seed. You need to stay one step ahead of the birds.
"They're very industrious, and they'll harvest as the seed matures," Dimitrov said. "Most of the native flowers, if you are to harvest the seed, you have to do it right after the flowering is over but before the seed pod explodes.
"So you have to harvest them a little on the raw side and let them dry out in a shady area, [as you] would dry herbs."
Sally Roth, author of "The Backyard Bird Lover's Ultimate How-to Guide: More than 200 Easy Ideas and Projects for Attracting and Feeding Your Favorite Birds" (Rodale), said birds will know before you when seed stalks are ready to pick.
"They know when they're ripe before most gardeners do," she said via email. "Test one by smushing and catching seeds in your hand: If the seeds are brown or black, they're ready; if green, not yet."
Roth, who offers more information at her website, sallyroth.com, says she often saves whole seed heads and stalks of seeds and bundles them together to hang out for the birds.
When saving individual seeds, she clips the seed heads into an open brown grocery sack -- a separate bag for each type of seed -- then rolls the top loosely and sets the bag in a dry place for a week or two. Then she rolls the top tightly and shakes the bag vigorously a couple of times to separate the seeds from other residue. Remove the dead flowers and seed heads and you're left with seed.
It takes about a week or two for seed heads and stems to dry out, and then you can keep them indefinitely, stored upright, Roth says.
Different types of seeds can be stored together, as you would any kitchen grain: in a fairly airtight container or canister. They'll keep for years.
Venelin Dimitrov of Burpee says these are all plants that not only beautify a landscape but can be harvested for birdseed:
Gaura (Gaura lindheimeri): Brown-red seeds are produced in the fruit. Let pods turn brown and gently remove them; the seeds fall out easily.
Bee balm (Monarda spp.): Seeds are tiny and require careful work. Take the dried flower heads and crumble them on a paper plate, then separate the seeds.
Purple coneflower (Echinacea purpurea): When the flower has faded and started to dry, pull the seed head and slice it in half top to bottom. Remove the seeds and allow them to dry.
Russian sage (Perovskia atriplicifolia): Dry the heads and carefully shake them to disgorge the seeds.
Black-eyed Susan (Rudbeckia hirta): Run your finger over the dried seed heads to release the tiny black seeds. 'Indian Summer' and 'Goldsturm' are two popular varieties.
Cosmos (Cosmos bipinnatus): Their delicate blossoms belie the rugged constitution of these popular plants. When colors start to fade, they start producing seed. Wait till one has dried, then pull the seeds from the flower head.
Lavender (Lavendula): Popular with goldfinches, who love the seed.
Sunflowers (Helianthus annuus is the annual, but there also are native perennials): Black-oil and striped seeds are the most common in commercial bird food, but any sunflower will provide tasty birdseed. Roth recommends clipping the entire head with a piece of stem and using it as a self-serve bird feeder.
Mexican sunflower (Tithonia rotundifolia): The bright orange flowers can take the summer heat. Deadhead them for the seeds -- dry the heads and pull out the seeds -- and they'll bloom until frost.
For more information on plants that provide birdseed:
Birds & Blooms magazine's website, birdsandblooms.com. Type "grow birdseed" in the search field.
National Bird-Feeding Society website, birdfeeding.org. Click on the "bird food" link.
"Bringing Nature Home: How You Can Sustain Wildlife with Native Plants" by Douglas W. Tallamy (Timber Press).