The 149-centre group is seeking to fill gaps in its national coverage for click and collect, with the centre distribution map suggesting the west country is under-represented.
Centre owners are generally resisting Wyevale's approaches after a strong season, around 10 per cent up in many areas of the country.
Gilbert Evans director Mike Gilbert said: "Garden centres are still trading well." He said owners needed a "good reason to sell", and many were carrying on for "lifestyle reasons" despite attractive offers.
He added: "I'm saying, if you're thinking of selling in the next five years, now is as good a time as any. There is a lot of demand for good quality garden centres. Each one that comes on the market gets four or five bids."
Several independents are developing their catering offer with Fron Goch, Knights Nags Hall and Ashtead Park developing restaurants with Pleydell Smithyman and centres such as Monkton Elm, Trelawney Probus and St John's developing too.