The best time to put out nesting material for birds is late February to early March in southern states, and mid-April in northern states. These dates give birds access to building supplies right when they start scouting nest sites, which is typically a few weeks before eggs are laid. Putting material out too late means most birds have already built their nests; too early and it may blow away or degrade before anyone needs it.
Nesting Season by Region
Nesting seasons vary significantly across the U.S., driven mostly by latitude and climate. According to USDA data, southern states like Texas, Florida, and parts of the Southeast see nesting activity begin as early as March 1 and run through mid-July. Mid-Atlantic and Midwestern states generally fall into an April 1 to August 1 window. Northern states and higher elevations start later, with places like Alaska compressed into a short May 15 to June 25 season.
A practical rule: put nesting material out two to three weeks before your region’s nesting season officially begins. That means late February for the Deep South, mid-March for the Mid-Atlantic, and early April for New England and the Upper Midwest. Birds scout nest sites before they start building, so having material available during that scouting phase is ideal.
Leave the material out through the full season, since many species raise two or even three broods per year. A robin that finishes one nest in May may build another in June. Some late nesters, like American goldfinches and cedar waxwings, don’t start building until midsummer because they time their breeding to coincide with seed and fruit availability.
Which Birds Start Earliest
Great horned owls are the earliest reliable nesters in North America, beginning courtship calls in November and nesting as early as January. Bald eagles and common ravens also start in the first months of the year. These large raptors collect their own sticks and won’t visit a backyard nesting station, but their early activity is a signal that breeding season is approaching.
The birds most likely to use materials you provide, like chickadees, titmice, nuthatches, and wrens, typically begin nesting in April. House sparrows and European starlings often start earlier, sometimes while snow is still on the ground, because they nest near buildings where warmth from heating vents gives them a head start. If you see any of these species carrying items in their beaks, nesting is already underway and you should get material out immediately.
Safe Materials to Offer
The U.S. Fish and Wildlife Service recommends sticking to things birds would naturally find: small twigs, dried leaves, moss, lichen, and untreated grass clippings. Short pieces of natural plant fiber, straw, and pine needles also work well. Cut or break everything into pieces no longer than three to four inches. Longer strands of any material pose an entanglement risk.
You can pile materials on the ground in a visible spot, drape them over shrubs, or stuff them into a clean suet cage hung from a tree branch or hook. Suet cages work especially well because birds can pull out individual pieces without scattering the rest, and the cage keeps materials from blowing away in wind.
Materials to Avoid
Several commonly suggested nesting materials are genuinely dangerous, and the list may surprise you.
- Human hair. It’s long, thin, and remarkably strong. Hair can wrap around a bird’s leg or wing and cut off circulation, sometimes severing the limb entirely. One bird rehabilitator compared it to wrapping a strand around your finger until it turns white.
- Pet fur treated with flea or tick medication. A University of Sussex study found harmful chemicals in 100% of the bird nests they tested that were lined with animal fur. Every single nest contained fipronil, a flea treatment chemical banned for agricultural use in the EU. Nests with higher chemical concentrations had more unhatched eggs and dead chicks. If your pet has been treated with any topical flea or tick product, do not offer their fur.
- Dryer lint. It seems soft and perfect, but lint crumbles when wet and retains moisture. A nest lined with dryer lint can become a cold, soggy trap for eggs and chicks after rain. Lint also contains synthetic fibers and chemical residues from detergent and fabric softener.
- Yarn, string, and fabric strips. Any long, flexible synthetic material can tangle around legs, wings, and necks. Even short pieces of yarn can bind as they get wet and tighten.
The Sussex study found 17 different insecticides across the 103 nests they tested. The chemicals came primarily from veterinary flea and tick treatments on household pets, not from agricultural sources. This is a meaningful finding for anyone who grooms a dog or cat outdoors, since birds readily collect shed fur from lawns and decks.
Keeping Materials Fresh
Natural materials degrade over time, especially in rain. Check your nesting station every week or two and replace anything that looks matted, moldy, or waterlogged. If you’re using a suet cage, a quick rinse with water and a scrub with a stiff brush between refills keeps things clean. Mold and bacteria thrive in damp organic material, and you don’t want to introduce pathogens to a nest.
Position your station in a spot with some overhead cover if possible, like under a tree canopy or the edge of a roof overhang. This extends the life of the materials and keeps the station visible to birds that are already foraging in sheltered areas. A location near existing shrubs or trees is better than the middle of an open lawn, since nesting birds prefer to grab material close to cover where they feel safer from predators.
What Helps More Than Nesting Material
Offering nesting material is a nice supplement, but the single most effective thing you can do is leave parts of your yard a little messy. A brush pile in the corner, leaf litter under shrubs, dead flower stalks left standing through winter: these provide exactly the twigs, bark strips, dried grass, and spider silk that birds need, right where they naturally look for it.
Native plants are especially valuable. They produce the seed heads, fibrous stems, and insect habitat that birds depend on throughout the breeding season. A yard with native shrubs and perennials will attract nesting birds whether or not you hang a suet cage full of moss. The material station is a bonus on top of good habitat, not a substitute for it.