The horticulture industry body is warning consumers to expect vegetable prices to remain high due to a wet winter over much of the country.
Food prices were 2.7% higher in August than July, the largest monthly increase for 19 years, according to latest Statistics New Zealand figures.
Vegetable prices rose 14.5%, driven by higher prices for lettuce (up 33.6%) and tomatoes (up 42.8%).
Over the year to August, fruit and vegetables increased in price by 19.1%.
Vegetable growers throughout the country are reporting a continuing battle with too much rain and hail and low light levels.
Stan Clarke from the Pukekohe Vegetable Growers' Association says his region had almost half a metre of rainfall during July and August, leaving soil waterlogged.
He says the constantly wet conditions meant foliage on many crops deteriorated, especially on leafy vegetables such as lettuce and brassicas.
When vegetables grown in these conditions are harvested, a lower proportion than usual of the crop is suitable for marketing.
Earlier this year Horticulture New Zealand said heavy winter rainfall cut some crop yields by more than a third, and a reduction in supply was driving up prices.