Scotsdales managing director Caroline Owen said: "On Sunday we were down 20 per cent and on Saturday five per cent. We were level on Monday so about seven per cent on the weekend. That's not too awful considering the weather.
"But bedding is a couple of weeks behind. We've had a lot of people in the planteria buying replacements for plants that have died in the winter, such as Hebe.
"The weather was so bad we had to move Clematis off the sales area because of the risk of snapping, but the figures go to show that, as a garden centre without a big cafe or gift area, there is demand for core gardening."
Squires managing director Dennis Espley said: "It wasn't very jolly. But the week wasn't as bad and for April we were 10 per cent up on last year, so we can take the past few days in our stride. We've done very well because April 2009 was fantastic so to have another good April is excellent.
"Garden furniture and anything outdoors are not doing well. Slightly more worrying is that the weather forecast for next weekend is cold again. Bedding plants are key and have been slow."
Squires was 14 per cent down for the week ending Sunday 2 May and 25 per cent down over the bank holiday weekend. Millbrook in Kent said the weekend was its worst since February. Shoots in Sussex called sales "decidedly average".
But Webbs in Worcestershire bucked the trend with "an excellent weekend overall" and sales from Thursday to Monday up by 16 per cent. Dobbies, Barton Grange and Raylon also did well.
Garden Centre Association (GCA) chief executive Gillie Westwood said: "I don't think anyone had a good bank holiday."
Early GCA figures showed garden centres were three per cent up on average for April, with outdoor plant sales 0.26 per cent up. Year-to-date figures showed garden centres three per cent down on 2009.