The Horticultural Trades Association says the 'average' garden season has returned after unusual weather patterns in recent years disrupted garden retail sales.
Latest figures from the HTA Garden Retail Monitor show that garden retail sales for the first five months of 2014 are 21% up on last year.
Illustrating the return to a normal season, the monitor also shows that garden centre sales for May were only 2% up on last year, but sales for March were up 77% and sales for April were up 21%.
Chief executive of the HTA, 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."