When is the best time to treat a yellowjacket nest?

The most effective time to treat a yellowjacket nest is in the spring at night. During this time, the yellowjackets are less active, and the colony is typically smaller as it is just starting to grow. Treating the nest at night reduces the risk of being stung because the insects are more likely to be inside the nest and less responsive to disturbances.

In contrast, treatments in the fall during the day would involve confronting a larger and more aggressive population, as the colony has fully developed and is preparing for winter. Summer at dusk may also present challenges, as yellowjackets are becoming more active in the evening, and there is still a risk of stings. Winter in the early morning is not ideal since most yellowjackets would be dormant or dead, making it ineffective for nest removal or treatment.