Castleton site, which is "just down the road" from another Wyevale centre, to convert to nursery to supply other centres in the chain.
The company explained that the site on Newport Road will be turned into a nursery as it is just one mile from another garden centre in the Wyevale chain, Blooms Cardiff Garden Cente. The change also means that Castleton can supply plants to its other centres in Wales.
Wyevale chief executive Nicholas Marshall said: "Due to demand for British-grown plants and the fact we have another garden centre just down the road, we will be closing Wyevale Garden Centre - Castleton and converting it into a commercial nursery, so all of our garden centres in Wales can provide their customers with plants grown in Welsh soil."
He added that the existing Castleton team will be re-located to other Wyevale centres where possible and that Blooms Cardiff Garden Centre will welcome all Castleton customers and honour its gardening club membership.