GCA Barometer of Trade results - which surveyed 40 garden centres - show outdoor plants were hardest hit by wintry weather, dropping 32% compared to 2008.
Seeds and bulbs were 4.9% down but pets and aquatics, including bird food, were up 8.6%.
Year-to-date figures show seeds and bulbs are level with 2008 but outdoor plants are 31% down. Pets and aquatics are 12.6% up.
Average basket sales were up 2% at £18.70.
Some retailers cashed in on February's snow. Armitage's in Yorkshire sold 1,500 specially ordered sledges, collected by a delivery driver now known as the Ice Trucker, after the TV series.