The deal takes Gardman out of administration and includes all trading assets, stock, infrastructure and Gardman brands, which include Cole and Bright, Grow It, Moulton Mill and Gardman Wild bird care.
A spokesperson said that the immediate focus will be to work with all customers to provide as much continuity as possible and ensure a smooth transition over the coming weeks.
He added that the growth of wildlife, the increased interest in the outdoor space were factors in purchasing the business.
Edward Conroy, managing director at Westland, which has a large base at Driffield, said: “We have always believed that Gardman is an important part of the gardening landscape, and we are committed to maintaining this for the long term.
“Gardman is fundamentally a strong business with good products. Our focus is to work together with all customers to make the transition simple and clear to all. It is imperative that in the coming days we keep our lines of communication open with customers and stakeholders alike.
“Westland is focused on delivering a strong future for Gardman categories which can only thrive from being part of the Westland family.
“For now, it’s very much business as usual for all concerned.”