Neil Gow has told DIY Week, the further rise in interest rates announced by the Bank of England is another considerable blow to the economy.
Mr Gow's comments come after the fourth rise in less than 12 months. He believes it shows the "government's policy on inflation control is not working," and now hopes Tony Blair's departure from office will herald a "much needed change".
He said: "We need an active housing market for people to feel like spending in garden centres and other outlets.
"This latest rise means the average family mortgage will be costing around £87 more per month than it was this time last year, with our highest interest rate for 10 years."
The director added that coupled with the rises in March for the Shop Price Index of 0.69%, food prices rising by 3.6% means there is less money for consumers to spend on their gardens.
"It is just a good job we have had an early gardening season this year," he said.
"Garden retailers have got some cash into the bank. The good season so far is a long way short of what we need to make up for the past three years, but it will at least help cushion any downturn in trade this latest rate rise may bring"