"These cannabis operations always achieve good results, but it doesn't end there. We are constantly monitoring the activities of drug offenders and associated criminals. There will be no let-up."
A decision to fly over Napier and Hastings suburbs paid off, with a large number of cannabis plants growing in backyards spotted from the air.
Mr Foster said that dispelled the myth that cannabis was usually grown in rural areas away from the public's gaze.
"Cannabis growers will take their chances anywhere and we rely heavily on the public to tell us if they see anything suspicious in their neighbour's properties. While some of these plants were reasonably well hidden, some were in quite open view and would have been noticed easily. We urge people to contact us if they find or see anything to do with drug activity."
In Wairoa, police searched six properties where cannabis and firearms were found and arrested five people on cannabis and firearms charges.
Police searching a property in Gisborne found 430 mature plants growing in a back orchard. There was also a sophisticated growing room set up in a haybarn on the property.
Mr Foster said the trend towards indoor growing was increasing.
"These are usually quite sophisticated and well-hidden. Many cannabis growers are leaning towards this type of growing to try to avoid detection by police. Once again, we need to hear from people who notice any strange behaviour in their neighbourhood or rural area. This could be anything from strange vehicles coming and going from a property or horticultural equipment being brought onto a property. Any information like that is important to police."
Mr Foster said there was a link between drug offending and burglary, with many users committing burglaries to fund habits or pay drug debts.