Bayer technical manager Colin Mumford told an audience of growers that Exemptor was "the safest option" for vine weevil control.
He set out to expell "myths about neonicotinoids" saying the product, which contains thiacloprid at 10% is bee safe.
Growers can also use cultural and biological controls such as sticky bands, hand picking, nematodes and fungus, but Exemptor is effective on several pests including lily beetle and vine weevil, Mumford said.
He explained that the neonicotinoid imidacloprid has to be used inside a glasshouse and plants treated with it can't go outside for two years - and that clothiandin and thimethoxam are banned. However thiacloprid is a third generation neonicotinoid and is still authorised, and bee safe, as bees can metabolise it very quickly.
Exemptor also has a short half life and doesn't leach.
He said if bees consume 0.79mg of pollen a day, a lethal dose would be 21,794g or nearly 22kg of pollen, which would take a bee 2,000 years to eat.
Meanwhile growers at the event said they were concerned that B&Q was banning all neonicotinoids and needed to find alternatives.
More than 100 attended the event.
ICL sales development manager Martin Donnelly said Integrated Pest Management was the way forward:
"Ornamentals is all about the look of plants, edibles is about the yield, so it's harder for ornamentals.
"Some products you're using will drop off the edge," he added with metaldehyde under particular threat.
He recommended Exemptor plus nematodes for vine weevil and aphid control and said modern neonicotinoids were better than old alternatives such as pyrethoids, which were toxic to bees.
Donnelly also recommended parasitic wasps for aphid control and Prestop as a biofungicide.
HTA horticulture head Raoul Curtis-Machin said there was "frustration" ornamentals were being "targeted" as the EU mulled over whether to extend bans.
He said: "Regulatory bodies aren't banning them and the general direction of travel is to use less and less chemicals."
ICL technical manager Andrew Wilson spoke about using a holistic approach to plant nutrition and recommended Osmocote.
New is ICL's Bluemax hydrangea blueing agent with aluminium sulphate.
Also speaking were nursery consultant John Adlam on air-filled porosity management and APHA presented on xylella.