Dunnett told delegates that if urban greening is not loved by local people it is not sustainable.
In his speech, Dunnett advocated the use of wildflower mixes to create urban meadows as one way to help increase biodiversity. He said of the 300 people he had surveyed, most preferred the meadows to traditional bedding displays because they "change constantly".
Dunnett also called for more green roofs and rain gardens - depressions in the ground to hold rainwater.
He said the campaign for more biodiversity had opened up the world of garden design to commercial land, including the use of public car park strips to catch rainwater run off.