North One and West Six owner Beryl Henderson said sales in the first two weeks of October were the same as the whole of October 2015.
She said the "amazing" weather had helped sales rise by a five figure sum at each garden centre: "In the first two weeks of October we've sold what we did in all October last year."
Scotsdale's John Ashley said: "We've had very good sales [in October so far], all considerably up on the previous year at all our centres. Christmas is coming out in full force and people are shopping for Christmas already."
Alton Garden Centre director Andy Bunker said October had been going well and was an important month because it has good potential growth.
There was a lot of settled weather is expected during early October and Met Office forecasters predict:
"High pressure looks set to remain to the northeast of the UK, continuing to bring east or south-easterly winds across the country. These winds will become strong at times, with the risk of gales in places. Bands of rain may spread into the south-west at the start of this period, with the chance that some of this slowly spreading further north by the end of October.
"Eastern parts may see scattered showers throughout, but generally the further north you go the greater chance of remaining dry and bright. Temperatures are likely to turn milder across the south at first, but this often offset by the stronger winds. Where it remains more settled though, temperatures will be colder with an increased likelihood of frost and fog forming overnight."