He said he wanted to check on the centres ahead of the Easter weekend and two Bank Holiday weekends in May.
He added that like-for-like sales in March were up by 30% on last year and sales last week were up 34% on the same week last year. Since 1 January, sales are up 10% year-on-year.
Sales of grow your own plants are up by 50%.
Nicholas Marshall said: "The experiment of making Wyevale more like a DIY store has seriously failed. I am taking it back to a garden centre with plants first."
Wyevale now has 190,000 loyalty scheme members after a month of the scheme. Its target is 500,000 members this year.
Figures from Verdict Research estimate that sales in the sector this year will be 8.5% lower than last year at £3.3bn. Next year they are expected to fall by a further 3.3% to £3.19bn.