After "several years of decline", the category has seen growth in 2016 and 2017.
Sales and marketing director Adam Dunnett says: "This shows shrubs are making a comeback.There is demand from retailers and the amenity market too."
He says hydrangea Magical series, H. Miss Saori, H. LA Dreaming ad phormium Blondie are doing best.
Phormium production is up 60% with 40,000 3l pots and 8,000 7.5l.
Ceanothus 'Cool Blue, Cordyline 'Electric Pink', Magnolia 'Cameo', Syringa Boomerang Collection, Dianella Wyeena' and Ilex 'Littel Rascal' are other star plants.