Plant buyer David Mitchell said that while plant supplies are "out to tender at the moment", he expects just a "move around of the mix and not to lose anyone".
He added: "We're making sure we're dealing with the right people. Some people have better plants than others. It's about long-term relationships and stability." There is a "need to underwrite investment in stores", he said.
Wyevale will stock 70,000 Christmas trees from Ireland and will finalise suppliers from mid August. Existing suppliers "might stay on - aspects might change", said Mitchell, and Tim Clapp provided continuity at Wyevale after much change since Terra Firma bought the chain.
He added that bigger, more unusual trees are in demand, such as 8ft Frasers and lodgepoles. He added that there are cheaper trees on the market at the bottom end, which Wyevale is avoiding.
He said all poinsettias this year are from a mix of UK suppliers and prices will be the same as in 2013. "It's been a good season, more normal than 2013. We're up against tough comparisons now." The specimen market is stronger this summer as the economy recovers, he added.
Wyevale's Christmas offer features top-end Flora Botanica ranges at 16 "A" centres with a Rio opulent theme. A £3,699 crystal LED tree will be for sale, but LED reindeers from £14.99, outdoor lights at £49.99 for 10m, a £4.99 decanter and reindeer foot massager at £24.99 are more likely to be the most popular sellers.
Crystal Queen is at 48 centres, including a star item "bling" hedgehog at £14.99. Ranges at all garden centres include Fairy Forest and Enchanted Forest.