The 143-centre group grows 30,000 at its Woodlands Nursery and uses all British supply, including from Cobbins, which is growing 140,000.
Wyevale Garden Centres said: "At Wyevale Garden Centres all of our poinsettas are UK grown, and many are grown at our own Woodlands Nursery."
Wyevale Garden Centres marketing director Sarah Fuller said: "It is the only plant sold in complete perfection. All other plants are sold before their development process is finished. But the poinsettia is sold at its most beautiful and in full bloom.
"Our expert horticulturists grow our poinsettias in state-of-the-art computer controlled greenhouses based at our Woodlands Nurseries near Leicester.
"It takes eight weeks for their leaves to turn from green to red – with careful handling, their beautiful, bright red foliage is in full bloom by the time they hit the shelves – perfect for spreading a little brightness during the dull winter months."
Nursery manager Jamie Downes said: "The delivery of the poinsettias into our garden centres is when we know Christmas really has arrived. Every year we see an increase in demand for the poinsettia as shoppers are looking for that something extra to add to the decoration of their homes during the festive season."