March saw garden centre sales up 77 per cent on March 2013 according to the association's figures, while April was 21 per cent up. May sales were two per cent ahead of May 2013.
The figures are similar to GCA statistics, which saw its members up 16 per cent by the end of May, and around 2.5 per cent up for the month.
HTA chief executive Carol Paris said: "Many businesses are breathing a huge sigh of relief after better sales this spring. There is much talk of it being a ‘normal’ season’ and we mustn’t forget that sales didn’t really start last year until May 2013 which goes some way to explaining the huge gains this year plus the drop off in May.
"Whilst there are no guarantees that sales throughout the year will be equally good it is certainly a very good lead to have at a very important time of year for the garden industry."