Blue Diamond, which is mainly south England-based, said milder weather had led to a January sales uplift and south east-based group Squires was 10 per cent up in January.
Meanwhile West Yorkshire-based Armitage's was 4.4 per cent and 4.9 per cent up in its two centres for retail, but saw catering slightly down "because customers have not been able to get to centres for a whole weekend because of snow."
GCA chief executive Iain Wylie said: "Midlands northwards have fared slightly less well but there's variances in each region, Wales and west and Ireland have done well but there tends to be that N-S divide possibly because of the weather."
He added: "Catering is static on average, though certain centres have footfall clearly down."
Clothing has done well, bird care is a top performer at 15 per cent up, plants are static, seeds and bulbs and sundries are showing "healthy increases". Average overall gain is 5-7 per cent.
More snow in February has led RSPB representative Richard James to suggest providing bird food for wild birds.
Compared to last winter’s stormy weather, 2015 has been milder overall and that means fence sales are down on 2014.
Taylors Bulbs said it has a new spring display competition for garden centres and is seeing encouraging early sales of bulbs ahead new packaging being launched in its forthcoming catalogue.
Mr Fothergills Seeds said "early signs are pretty strong".