Garden Centre Association chief executive Iain Wylie said: "It could have been a lot worse. Three per cent is not unreasonable - it's manageable for most businesses."
But he warned that employees higher up the wage scale will want to keep their differential in wages.
HTA horticulture head Raoul Curtis-Machin said: "The increase is a good thing but we are trying to work with the Government for more slow-scale changes.
He added: "A big leap puts growers under too much pressure. If it doesn't happen in a measured way, it could lead to more growers shutting up shop."
However, Unite general secretary Len McCluskey said: "This increase is a slap in the face for low-paid workers struggling with a cost-of-living crisis. An hourly rise of 19p for adults is an insult when the minimum cost of living has increased by a staggering 25 per cent since the beginning of the economic crisis."