Why Does My Beehive Smell Bad? Goldenrod vs. Disease

As a new beekeeper, walking up to your urban hive and suddenly smelling something rotting, sour, or sweaty can induce immediate panic. Your first thought is usually American Foulbrood, a devastating disease that requires burning the hive.

However, before you reach for the matchbook, take a breath. In many cases—especially in late summer and early fall—that foul odor is completely natural and harmless.

Here is how to diagnose why your beehive smells bad, and when you should actually worry. For a complete guide to maintaining a healthy apiary, be sure to bookmark our Urban Hive Management & Health Hub.

The Harmless Culprit: Goldenrod Nectar

If it is August, September, or October and your hive smells like dirty gym socks, sweaty feet, or a sour locker room, congratulations, your bees find a patch of Goldenrod.

Goldenrod (Solidago spp.) is a vital late-season forage plant that provides massive amounts of nectar right when bees need to pack on winter weight. While the resulting goldenrod honey tastes delicious and buttery, the curing process inside the hive smells awful.

As bees fan the goldenrod nectar to evaporate the moisture, the pungent smell wafts out of the entrance. It can be so strong you can smell it from several feet away.

Diagnosis Checklist:

• Time of year: Late summer to mid-fall.
• The Smell: Musty, sour, sweaty feet.
• Inside the hive: The bees are active, drawing wax, and capping honey. The brood looks pearly white and healthy.

Action Required: Nothing. Let them cure their honey. (And if you are new to city beekeeping, check out our Ultimate Guide to Urban Beekeeping).

The Bad News: American Foulbrood (AFB)

If your hive smells like rotting meat, sulfur, or a dead animal, you have cause for concern. American Foulbrood is a highly contagious bacterial disease that kills larvae and pupae.

Unlike the musty smell of goldenrod, AFB has a sharp, putrid, necrotic odor.

Diagnosis Checklist:

• The Smell: Rotting meat or dead fish. Strongly unappetizing.
• Inside the hive: The brood pattern is spotty. Cappings over the brood cells look sunken, greasy, or punctured.
• The Matchstick Test: If you poke a sunken brood cell with a twig or matchstick and draw it out slowly, the ropy, decaying larvae will string out an inch or more.

Action Required: AFB is highly regulated in almost all cities and states. You must contact your local bee inspector/state apiarist immediately. Do not move equipment to other hives, as the spores are highly contagious.

Other Smells You Might Encounter

• Sour or Fermented Smell: If nectar or sugar syrup ferments inside a feeder, it will smell like cheap beer or sour fruit. Action: Remove the feeder, clean it with bleach water, rinse thoroughly, and replace with fresh syrup.
• Lemongrass Odor: This is the natural Nasonov pheromone! Worker bees release it by raising their abdomens and fanning their wings to guide other bees home. It smells sweet, citrusy, and wonderful.

When in Doubt

When you open the lid, a healthy hive should smell like warm beeswax, sweet honey, and fresh wood. If you encounter a foul smell, check your calendar. If the goldenrod is blooming, breathe easy. If the brood looks sunken and rotten, call in an expert.

Need help keeping your neighbors calm through hive issues? Read our guide on Swarm Prevention for Urban Beekeepers.