Sales were up five per cent in October, six per cent up in November and were 12 per cent up in December.
December 2011 sales were up seven per cent on 2009. Grow your own sales plateaued in 2011.
HTA marketing director Andrew Maxted said: "The garden industry ended the year in a good position and despite the gloomy economic outlook for the months ahead garden retailers remain cautiously optimistic in the light of events such as the Jubilee and the Olympics.
"Interest in grow your own continues and it looks like the category is maturing with people trying their hand at growing different crops after enjoying the fruits of their labours in previous seasons."
He added: "Research from Future Foundation shows that consumers are feeling the need to connect with rural life and are looking for authentic and local products.
"They are also looking for value and in a retail environment where three quarters think that they pay too much for food and organic vegetables ‘growing your own’ remains for many an attractive proposition."