The sisters, both great gardeners, said they ran the stand as a hobby, growing plants from cuttings or seedlings and selling them for $1 each.
Mrs Giles said she couldn't understand how anyone would get joy out of wrecking their plant stand and wondered if they should bother fixing it a seventh time.
"You spend a lot of time looking after the plants and to see them broken and smashed and the whole set up vandalised is heartbreaking.
"It's not a huge money earner but you get to talk to a lot of people who come back and see if there's anything new. You build up friendships with people and if we don't put the stand out all of that will go."
Mrs Layton said she had notified police about the vandalism but the identity or identities of those involved remained a mystery.
"This time there was a beer bottle left so the police have actually taken that away but up until now we've had no idea. One time I heard a car late at night but I wasn't going to go out and have a look.
"Yesterday we had neighbours say there was a party nearby and wondered if it was them. It could be anybody but I'm pretty sure it's the same person or people and they just think it's fun."
Having lived on Arataki Rd for nearly a decade, Mrs Layton said she and her sister were "torn" between putting the plant stand back together or finally letting the vandals win.
"It's frustrating, why do they think it's funny? I've got to the stage now where it's a challenge for them. They leave it a wee while and then think 'let's go do that plant stand again'.
"I'm torn between not letting them win and putting the table back out there once I fix it, but I'm kind of getting to the stage where I'm asking if I can be bothered."
A police spokesperson said they had received a report of wilful damage to a plant stand on Arataki Rd, reported to have occurred between 8.30pm on Friday and 7.30am on Saturday.
"The stand has reportedly been damaged six times in similar circumstances over the past two years. This is the first time it has been reported to police."
A forensic examination had been conducted and police would be aware of the matter over the coming weeks, they said.