Primrose managing director Ian Charles said "It’s all about the sunshine – you never know when the first really big day of the season is going to hit until you look at the pre-weekend weather forecast.
"We work hard every year at gearing up for big days like this – most of our products are offered on a next-day basis, so it’s crucial we don’t let anyone down. My colleagues on the phones and in our warehouses worked tremendously hard and efficiently to get the job done on the day.
"We’ve also continued to invest in even larger ranges of unique products available for next day delivery.
Charles added: "With over 100,000 product reviews and highly detailed product information, customers often have a much better understanding and confidence in the product than they have in store. They also have access to a vast range specialist products – they no longer need to have the same plants and decorative items that their neighbours have."
Primrose said sales uplift was "across the board" in all its categories.
Bricks and mortar garden centres have seen sales records broken too since May bank holiday after a slow start to the season.