Gardeners in Cornwall's National Trust properties are to carry out a count of all the plants which are flowering.
The trust intends to do a count on the same day every year to see if the county's climate is changing.
One of the trust's longest serving gardeners, who already counts the blooms at Trelissick Garden near Truro, believes it is getting warmer.
But Barry Champion said the heavy frosts and snow last November could affect this year's count.
He said there has been a rise every year since he began in the early 1990s, except for this year. His record is 220 species but this January the number fell to 78.