Families at the centre had been preparing for the stall for about five weeks, with the children helping to prepare "seed bombs", balls of potting mix and flower seeds wrapped in clay, at the centre this week.
"It's good that the kids can help as well and it's meant that we can all be on the same team, trying to make our centre better and safer," Mrs Williams said.
The stall will also be selling home-made preserves, veges and other produce-related items, all made at the centre or by parents at home.
There will be a "guess the weight of the giant pumpkin" competition and an interactive musical performance picnic area.
Mrs Williams, whose daughter has been attending the playcentre for about year, said it provided great resources.
"They have the resources and equipment that I don't have at home and it's also the interactive and parent-run side of it, because I'm at home with her it gives me somewhere to go and do stuff with her, I don't just drop her off and leave.
"It's somewhere that you can go and make a mess and not worry about it."
The playcentre has plans to run another stall at Christmas but might run more if this weekend turns out to be a success, Mrs Williams said.
The playcentre also welcomes donations to its Givealittle page.
"Even if you just give $1, we appreciate every little bit."