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Hen of the woods at the base of the same oak year after year

September to October

Hen of the woods is a big gray-brown mushroom that grows in overlapping rosettes at the foot of living oaks. The same oak often produces one year after year, so an oak that had one last fall is worth checking again this fall.

Why this time of year

In southern New England these are most abundant from mid-September to early October. This is a looking card and not a foraging card: the point is that a fungus has been quietly rotting the roots of that oak for years and this is the fortnight it shows itself.

How to notice it

  1. Walk a slow circle around the base of any big old oak, in woods, a park, a cemetery or a street planting.
  2. Look for a rounded clump of overlapping fan-shaped caps sitting low against the bark, gray-brown on top and white underneath. A full one can be as wide as a car tire.
  3. Widen the circle a few feet out. These sometimes come up over a root well away from the trunk rather than touching it.
  4. Photograph the tree or fix it by a landmark. If it produced this year, check the same trunk next September.

Try this with kids: The part you can see is only the fruit. The rest of this fungus is inside the tree's roots. How much bigger do you think the hidden part is?

a polypore drops its spores through tiny pores under its caps instead of through gills

Safety

  • Never eat a wild mushroom. Look, photograph, and leave it where it is.
  • Several similar mushrooms grow at the base of oaks, including the black-staining polypore and Berkeley's polypore, and telling them apart is not something to try on a walk.
  • Do not pick, dig or pull at the clump. Foraging, including picking mushrooms, is prohibited at all Mass Audubon wildlife sanctuaries and on many town conservation lands.
  • Wash hands after touching any mushroom or the soil around it.

Sources

  • umass.eduUMass Extension, and the load-bearing source for every element of this entry: fruiting bodies appear anytime from late summer through autumn but in southern New England are often most abundant from mid-September to early October; oaks are the primary host; rosettes grow from the soil at the base of infected trees and at times from roots a few feet away; mushrooms may appear annually for many years around the base of an infected oak; the fungus causes a white pocket rot of roots and lower trunk. It also states that oaks with fruiting bodies at the base are not necessarily at high risk of failure, which is why this entry carries no tree-hazard warning.
  • mdc.mo.govMissouri Department of Conservation field guide, corroboration only: grows on the ground at the base of oak trees and is often found on the same tree year after year; season September through November; the gray-brown-above, white-beneath description; and the two lookalikes named in safety_notes, the black-staining polypore and Berkeley's polypore.
  • massaudubon.orgMass Audubon, and the basis for the safety notes: never pick mushrooms to eat unless absolutely confident of the identification, and foraging including picking mushrooms is strictly prohibited at all Mass Audubon wildlife sanctuaries.

Checked against these sources on September 9, 2026.

In the guide for September, October

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