The Hertfordshire-based firm will carry out work in the local authority's formal parks, esplanades, cemeteries, churchyards, highway verges and some countryside areas in a six-year deal worth around £1m annually.
The portfolio will entail a range of work including grass cutting, planting and managing flower beds, cleaning ponds and water features, sweeping leaves and managing shrubs, clearing litter and grave digging.
John O'Conner founder and chair John O'Conner said: "The Isle of Wight has outstanding landscapes and wildlife and sustaining the island's beauty for both residents and visitors alike is a top priority for us. We are looking forward to working with the council and the island community over the coming years."
The decision to combine a number of separate contracts into a new single-package deal has helped to save the local authority around £1.8m.
It has revised its machinery and horticultural methods and reduced the number of areas mown each year to bring down costs in line with Government-imposed budget cuts.