Guide

Look closerPlants

Birch seeds and catkin scales on the snow

January to February

Under a birch in winter, the snow can be dotted with tiny winged seeds and three-lobed scales from the tree's seed catkins. The catkins come apart bit by bit, and wind slides the seeds across crusted snow.

Why this time of year

Gray birch, a tree of old fields and forest edges, sheds seed from October through the middle of winter, and many paper birch catkins stay on the tree into spring, dropping seed all the while. The National Park Service says that where paper birches grow you are bound to notice the seeds scattered across the snow. Good paper birch seed crops come about every other year, so some winters show more than others.

How to notice it

  1. After a snowfall, stand under a birch with white bark and look at the snow around your boots.
  2. Look for two kinds of specks: tiny winged seeds, and three-lobed scales. The National Park Service says they call to mind birds and butterflies.
  3. Check how far the specks reach past the branches; on crusted snow the wind can carry them far from the tree.
  4. No snow on the ground? Pick up a fallen catkin and crumble it on your palm to see the same scales and seeds.

Try this with kids: Find a three-lobed scale on the snow under a birch, then find a seed with wings. Does either one look like a bird to you?

Good to know: Catkin scale (bract): the small three-lobed flake that held the seeds inside the birch's seed catkin.

Safety

  • Gray birch grows at the edges of wetlands; look from solid ground and do not walk out onto ice to reach a tree.

Sources

  • fs.usda.govUSDA Forest Service FEIS (primary, federal species review, 1992 entry), gray birch timing and seed eaters: 'the fruit ripens from September to October. The seed is dispersed from October through the middle of winter.' Also: 'songbirds such as the pine siskin and chickadee feed on the seeds.'
  • web.archive.orgUSDA Silvics of North America, paper birch (primary, federal; archived snapshot because srs.fs.usda.gov did not resolve). Timing: 'Some paper birch seeds may be collected from August through the following spring, but most are dispersed during the months of September through November.' Snow: 'some seeds travel great distances, particularly when blown across the surface of snow.' Eaters: 'The redpoll, pine siskin, and chickadee feed on seeds.' 'good seed crops occur every other year on the average' (quote confirmed by the refute pass 2026-11-10).
  • web.archive.orgUSDA Silvics, yellow birch (primary, federal; archived snapshot). 'the first heavy seedfall in Canada and the northern United States comes with cold weather in October.' 'blown up to 400 m (1,320 ft) over crusted snow.' 'Yellow birch seeds dispersed in the fall and winter germinate... in early June.' 'The common redpoll and many other songbirds eat yellow birch seed. Ruffed grouse feed on the catkins, seeds, and buds.' Red squirrels 'eat seeds, store mature strobiles.'
  • web.archive.orgUSDA Silvics, sweet (black) birch (primary, federal; archived snapshot). 'Seed fall is during mid-September through November. Seed dispersal is normally by wind and seeds may be blown some distance over crusted snow.' Seeds 'are contained in erect strobili.' This shows black birch mostly sheds in fall, not winter.
  • nps.govNational Park Service, Northeast Temperate Network (primary, federal agency article). 'Many catkins stay on the tree into the spring, dispersing seeds all the while.' 'look down - you are bound to notice birch seeds scattered across the snow.' Photo caption: 'paper birch seeds, evocative of birds and butterflies.' Seeds are '~2mm long'.
  • urbanhabitats.orgUrban Habitats journal, peer-reviewed study of gray birch seed dispersal at a New Jersey site (primary research, secondary for timing). 'Catkins of gray birch tend to be persistent, lasting well into the winter. The scales and seed tend to separate first at the tip of the catkin.' 'Gray birch (Betula populifolia) is a pioneer species that commonly invades old fields' (quote confirmed by the refute pass 2026-11-10).
  • gobotany.nativeplanttrust.orgGo Botany, Native Plant Trust (authoritative New England flora). Lists Massachusetts among the New England states for paper birch, and describes its 'scales of fruting catkins with divergent lateral lobes' (the three-lobed bract shape; the typo is the source's).
  • gobotany.nativeplanttrust.orgGo Botany, Native Plant Trust. Gray birch: 'New England state Connecticut Maine Massachusetts...'; 'Specific habitat edges of forests edges of wetlands forests'. Basis for the woodland-edge habitat and the shore safety note.
  • gobotany.nativeplanttrust.orgGo Botany, Native Plant Trust. Yellow birch occurs in Massachusetts ('New England state Connecticut Maine Massachusetts'); habitat 'edges of forests forests swamps'.
  • blogs.massaudubon.orgMass Audubon blog 'An Epic Winter For Nomadic Finches', 2018-12-05 (secondary, Massachusetts). Redpolls 'specialize in eating birch catkins, and birches are the best place to look for them'. These finches irrupt only some winters ('Every few winters').
  • northernwoodlands.orgNorthern Woodlands, The Outside Story, Bill Amos, 2009-02-09 (secondary, Vermont observation, not on the preferred roster; supporting only). Under a paper birch in midwinter 'the spots were hundreds of tiny winged seeds', spread 'some hundreds of feet from their tree' on an icy crust. 'No such transport would have been possible on mushy snow or during a snowless winter.'

Checked against these sources on November 10, 2026.

In the guide for January, February

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