Shopkeepers were left to pick up the pieces after hanging baskets were pulled down and damaged by vandals.
The baskets on High Street are part of this year's Upton in Bloom bid.
Bill Dovey, owner of Gifted, was among those who discovered the damage on Sunday morning.
"The basket chain was broken and the flowers damaged," he said.
"I repaired the chain and put it back up myself but several other baskets had to be repaired.
"It's the first time it's happened this year but it has happened before, some of them have even been stolen.
"Why people do this, I just don't know. It's always pointless."
Mr Dovey said baskets at The Map Shop and estate agent John Goodwin were also damaged in the attack on Saturday night.
Mr Dovey said he had not yet informed the police but intended to do so.
Eric White, chairman of the Upton-in-Bloom committee, said: "This has happened a couple of times before, usually in the first week of the campaign.
"It's just somebody doing it to fool around. Most towns have the same problem."
Coun White said the baskets were back in place by Sunday evening and no permanent damage had been caused.
Last year, Upton scooped gold in the large village category of the Heart of England in Bloom competition. This year's organisers hope to go one better and win the overall regional title.
"We're very positive this year," said Coun White. "You do your best, but it's in the lap of the gods really. At least it makes the town look bright and cheery."
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