It claims to be taking share from competitors"in a static market".
The company says its "one-stop-shop approach" to peat-free and peat-reduced growing media with the Vital Earth and Growise brands, plus fuels, is helping sales to the garden centre sector.
Head of consumer UK Steve Harper said: "This is all down to supplying a consistently quality product that delivers for consumers as well as being in tune with the market’s gradual shift towards peat reduction.
"When we get the likes of Which? Gardening verifying our product performance, then this can only add to retailer confidence in working with Vital Earth and Growise, something which is clearly showing in the figures."
Meanwhile, Which? Gardening has recommended Vital Earth tub and basket compost as the best peat-free for container planting.