Forest Garden has bought M&M Timber which supplies wood products such as fencing and sheds to the UK garden centre sector.
M&M's products "will dovetail smoothly with Forest’s existing portfolio", say Forest.
The acquisition will also allow M&M to focus on further developing its offer into the landscaping, agricultural and play equipment markets with the support of Forest.
The two businesses are situated close to each other in Worcestershire. Forest has a turnover of about £50m, while M&M turnover is around £6m, with employee numbers of about 70.
M&M managing director Nigel Poyner said: "We are excited by this new chapter in M&M’s history; with the support of Forest we will now be able to invest the time and resources needed to develop our more specialist markets that we have for so long sought to focus on."
Forest Garden group chief executive Guy Grainger said: "I am delighted to welcome M&M into our business. The opportunities this brings, not just to M&M but to us collectively, are significant. All of our customer channels will feel the benefit of this acquisition from a wider product and service offer to new innovations from the timber technology now available to the group."