Thieves broke open a gate and stole nearly 70 Christmas trees from Stubbings Nursery last week.
Security has been increased at the site in Henley Road from which the cut trees, shipped in from Ireland and collectively worth about £2,000, were taken.
Police were called at 8.30am on Wednesday last week following the raid which had happened overnight.
A number of trees were left scattered in the field next door where tyre marks could also be seen.
Police are appealing for anyone with information or who has been offered a cheap Christmas tree to contact Sgt Adrian Blades via 101.
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