However, Lewis said the incident raised wider issues related to roadside planting.
The council understood residents wanted to beautify their areas but staff didn't know the plantings existed and hence the need to avoid spraying the area.
The main, concern, however, was the safety of road users.
''Plantings can reduce visibility for drivers and frequently encroach on to the carriageway over time, further compromising road safety. They can also interfere with overhead power lines. In urban areas, tree roots often damage underground water, sewer and other services, increasing maintenance costs for ratepayers.''
Lewis said the council wasn't opposed to people carrying out roadside plantings but they should seek advice to ensure road safety and services weren't compromised.
However, one of the Waimate North residents who raised concerns about the spraying said very few of the trees affected driver visibility.
John Beachman said the choice of targets was ''baffling''. There were many instances where one tree had been sprayed but the tree next to it, which was closer to the road, had not.
The pōhutukawa were planted in the late 1990s in a community project led by the late Bob Molloy of Kerikeri, who wanted to create a ''crimson trail'' stretching from Kaikohe to Paihia via Waimate North.