Her eye-catching romantic heart-shaped parasol picked up a gold award yesterday and put her top of the 13 finalists.
Melanie, 38, who has been running her shop, Passion Flowers, at Upton, Pontefract, for 12 years said she felt "just ecstatic, fantastic".
She has had success before, including major wins at Harrogate and the RHS show at Tatton Park, "but this is just something else".
"I said when I became a florist I would go in for Chelsea and now I have done it. I just love competitions."