Monty was questioned by a viewer after he praised the Gardeners’ World presenters.
He’d taken a week away from the show as Frances Tophill and Arit Anderson took over the reins.
Posting about their appearance in view of his 231,000 followers, Monty congratulated the duo.
He wrote: “Congratulations to Arit and Frances and the team for a brilliant GW last night. I loved it.”
When Gardeners’ World first began, it only ran for 30 minutes.
Then in 2016, executive producer Paolo Proto extended the programme to one hour.
Viewers were mixed in response to Monty’s reply about the format of the show.
One penned: “I thought it was just me.
“Found it a bit boring last night to be honest and would like more practical tips rather than skipping off to someone else talking about how wonderful it is that they’ve got a greenhouse in their spare room.”
However, others defended the gardening show, agreeing with the broadcaster.