Garden Centre Group hit the headlines after challenging Easter Sunday trading laws to open 73 centres to sell food and display ranges to its 892,000 garden club members. The HTA cautioned against the move on legal grounds.
Dobbies, which said Easter was "obviously disappointing due to extremely adverse weather", planned to open a planteria in Ponteland but is understood to have decided against doing so at the last minute.
Latest Garden Centre Association (GCA) figures show that sales figures for March were five per cent down on last year and 4.5 per cent down on the year to date.
Scotsdales managing director Caroline Owen said Easter Monday sales were four per cent down and Easter Saturday was level, although Good Friday was 20 per cent down because of poor weather. She added that calls for extended Sunday trading would be sidelined by the 6 May general election.
The retailers Sir Philip Green and Debenhams chief executive Rob Templeman have already written to business secretary Lord Mandelson asking for extensions to Boxing Day 2010's - a Sunday - restricted hours.
GCA chief executive Gillie Westwood said: "Sunday was the best weather in many places and centres couldn't open."
Northumberland-based Cowell's owner Alan Cowell said Easter sales were 40 per cent down on 2009, adding: "If it's not the weather to blame, we're in trouble."
Klondyke Strikes chief executive Bob Hewitt said Easter sales were "disappointing" at 27 per cent down. Squires managing director Dennis Espley said Easter sales matched 2009.
HTA retail committee chair and Haskins buying director Philip Evason said: "Although there were plenty of customers about, they were not purchasing core garden products in volume."
Cheshire-based Bents representative Helen Bent said it had missed out on Sunday, which was the best day of the weekend weatherwise. Footfall was down by more than 1,000 people on Friday and Saturday but up 400 on Monday, making customer numbers 17,000 compared to 18,000 in 2009.
She added that conversion rates were higher than 2009 but "generally outside products did not sell well over the Easter weekend".
Gwent-based Raglan Garden Centre owner Martin Davies said turnover was "half-a-week behind" this year and "quite well down for the Easter weekend".