Burks said: "Sales are very positive, albeit against two indifferent Mays in 2014 and 2015.
"However its the product mix that's interesting with really positive trends in core product especially plants. The last few weekends have felt like the old days with full trolleys heading through the tills and compost flying out.
"This means that we have caught up lost sales from April and a bit more which is good news of course."
A strong bank holiday weekend at the start of May heralded record garden centre sales days following a slow March and April with plants doing best.
After strong bedding sales Ball Colegrave suggested growers might be looking for young plants to start a new crop to meet demand.
Alton Garden Centre, Scotsdales and Longacres broke records with weather-frustrated gardeners seeking plants.
Centres including Scotsdale and Haskins said they were moving back to budgeted sales year-to-date.
Blue Diamond managing director Alan Roper said 2016 had started well for the group.
After a slower than expected start to the year owing to the cold weather, Blue Diamond is performing ahead of the industry and trade is strengthening thanks to the brighter weather, Roper said.