More than 100 children, parents, staff and gardeners from more than 60 schools and community garden all over the capital met at Clark House, the prison's staff training school to collect tool starter packs and watering cans for their gardens.
The donated tools have been refurbished in Wandsworth Prison's workshops before being given free to schools and community groups.
Tools Shed has been piloted with HMP Wandsworth. HMP Moorland near Doncaster and HMYOI Thorn Cross near Warrington have recently joined the programme and HMYOI Feltham is soon to come on board.
Conservation Foundation director David Shreeve said: "We're delighted to have the support of so many of the horticulture industry's big names to collect tools for us but are always looking for more collection points around the UK."
RHS head of education Ruth Taylor said: "We know lots of schools want to start school gardens but lack funds and resources."
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