June sales were 3% up and year-to-date 13% up in the planteria, with the total centre sales "very similar" said Alton Garden Centre director Andy Bunker.
He added negative May sales were less important than combined April and May, and the year-to-date figures.
May was 5% down across nationwide centres, leaving year-to-date sales figures at 6.4% up. April was 33% up in outdoor plant sales and left centres 11% up year-to-date overall, according to GCA figures.
"There was no way we could continue or indeed sustain the fantastic sales of certainly April but in some cases like mine, March being plus 46% and plus 47% respectively.
"In my opinion there are just two figures needed at the end of May, firstly year-to-date and secondly April and May together.
He says Essex-based Altons was plus 16% year-to-date at the end of May and and April/May together a healthy plus 9%, which was also the best ever two month combined even beating the heady heights of 2011.
Bents Home and Garden managing dietcor Matthew Bent said May and June have been "there or there abouts on last year" with poorer weather hitting sales after a "fantastic" April. He said consistent weather was needed to improve business this summer.