The seminar, hosted by York City Council at Knavesmire Racecourse, included an opportunity to question Chemicals Regulation Directorate environmental policy adviser Grant Stark.
More than 50 delegates from 12 councils attended the seminar, reflecting the growth of the regional group since its inception in 2008.
Founding member Mark Dempsey, of Calderdale Council, explained: "The UK now has to reassess the way that it uses pesticides and the amount that it currently uses. This needs to be integrated into a more holistic approach on managing pesticides in the amenity sector."
Joint event organiser Gary Harland, from Wakefield Council, added: "The event was a success despite the weather. We continue to build on the principles of best practice, sharing knowledge and networking within the Northern Amenity Forum."
He continued: "This has now led to the possibility of similar regional groups forming in the south of England and Wales based on the northern model."