The shares, which stood at 592.5p in June, lost a third of their value to close at 148p after the company said full-year profits would be "not less than pounds 5m".
This compares to pounds 6.25m last year. The group will cut the off-the-page advertising for its troubled Gardening Direct operation by a third from this year's figure of pounds 3m. It will focus on its database of customers instead.
Flying Flowers will give a detailed statement to shareholders with its interim results on 2 September. Nigel Smith has resigned as managing director of the company's DPA subsidiary.