52 bags of compost taken in raid on Springbank Nurseries in Winford at the weekend.
The incident is reported to have taken place at around 11pm on Saturday, March 5. The garden centre, off Winford Road near Newchurch, also sustained damage to its perimeter fence.
Hampshire Police have released details of a possible suspect, describing a white male, approximately six foot tall and wearing a hat and jeans.
A police spokesman said: "Police are pursuing several lines of enquiry in the community. It's believed a van was used to transport the stolen compost bags. We're particularly keen to hear from any witnesses who might remember seeing anybody acting suspiciously, or a van being driven in the Winford and surrounding areas late on Saturday night or Sunday morning."
Hampshire Police are also investigating a string of burglaries in the Eastleigh area, as thieves targeted the Arturi's Garden Centre site on Allington Road twice in just over a week. A spokesperson said the two burglaries were part of "a number of similar incidents that have occurred in the wider area of Allington Road in recent weeks."