Titchmarsh also launched what could be seen as a criticism of new Gardeners’ World presenter Monty Don’s claim that he hasn’t visited a garden centre in a decade.
He told 300 GCA delegates:
"To people who say they have not been to a garden centre for 12 years, I feel very sorry and if they are from the industry I feel very angry.
"They should be doing more to support the industry."
Monty Don said last year he had not been to a garden centre for 10 years but later Titchmarsh said he never criticises other presenters.
Titchmarsh added: "I’m coming back on the box doing gardening you’ll be horrified to know. There will be an announcement in the next couple of weeks."
Commenting on the dropping of industry favourites Toby Buckland and Alys Fowler in favour of Monty Don and Rachel de Thame in a quest to drive up Gardeners' World viewing figures from under 2m, Alan Titchmarsh said:
"You have to be realistic. TV is so different now even from when I was doing Gardeners’ World. There were only four channels and we got 5m viewers. No one is going to get that now except maybe Downton Abbey."
He added, obliquely referring to RHS president Elizabeth Banks’ comments last year on Gardeners’ World:
"I get angry when people talk about dumbing down-it’s a catch all term. I want to reach out to as many folk as possible."
It seems foolish that some think "the only way forward in gardening is towards specialism and elitism", Titchmarsh continued.
"My raison de etre is to reach as many people as possible. The important thing is that when we talk about warehouses, garden centres and nurseries is that there is room for them all. The key thing for all of them is that they shouldn’t disappoint."
Garden centres are "only as good as your worst plant", he said, adding that it was "no longer enough to have A-Z beds of shrubs" and called on retailers to inspire children into gardening and away from TV and computer games by showing them the "tactility of plants and soil: "If we’re not careful children will lead completely vicarious lives-they do nothing physical."
Titchmarsh said he when started gardening in 1964 there was a bare root season from November-March and then gardening to the end of May for bedding. He applauded garden centres for now "staying alive" for the rest of the year through opening restaurants and selling other goods "provided plants don’t take too much of a back seat".