1,000-Plus Rare Tower Mustard Plants Grew Up in London Homes. Now They’ve Moved Out

Tower mustard, a tall wildflower with small white blooms, had dwindled to just two known sites in London. This year, volunteers grew more than 1,000 of the plants at home and then planted them out across the city, according to a BBC report and the project’s leaders.¹²

The BBC calls it a successful first year for the community-led effort. The new plants have only just gone into the ground, so whether these populations survive and establish themselves is not yet known.¹

Why one mustard matters

Tower mustard is listed as Near Threatened on the Great Britain Red List. It has declined steeply as its habitat was destroyed and the way land is managed changed.⁵ It is thought to survive at around 30 sites across England.⁴

The plant grows to about a meter tall. Its flowers feed pollinators, including native bees, butterflies and rare moths.⁴⁵

How the plants were grown

The project is led by Citizen Zoo and Habitats & Heritage. It brings together land managers, community groups, conservation partners and volunteers.¹³

In March, the volunteers, known as the “Mighty Mustard” team, went to a workshop to learn how to sow the tiny seeds. They went home with pots, seed trays and soil.¹

The seeds came from the last two London populations: Lesnes Abbey Woods in Bexley and Stain Hill Reservoir in Richmond upon Thames. Botanist Dr Mark Spencer provided expert support throughout.¹

“Through this tower mustard project, we have enjoyed giving local residents the unique opportunity to get hands-on in conserving one of London’s rarest plants,” Charlotte Harris, nature conservation manager at Habitats & Heritage, said in the BBC report.¹

Where the plants went

The home-grown plants have now been planted at Wimbledon Common, Hounslow Heath, Lesnes Abbey Woods and Barnes Common.¹ A final planting day at Hampton Court Palace’s Home Park uses plants raised by the Historic Royal Palaces Gardens Team and volunteers.¹

When the scheme launched in February 2026, the goal was to establish new plants at five suitable sites across the species’ historic London range.⁴ Funding comes from the Mayor of London’s Green Roots Fund and Thames Water, with Hounslow Council and Lampton Countryside Rangers among the partners.⁴

This is Citizen Zoo’s first plant project in London. The group’s earlier schemes involved beavers, water voles, German hairy snails and white storks.⁶ The mustard project builds on its Hop of Hope scheme, in which volunteers reared large marsh grasshoppers at home.⁶ By comparison, a tray of seedlings is a very quiet houseguest.

What comes next

At the launch, Elliot Newton, Citizen Zoo’s director of rewilding, framed the project as a demonstration. “By putting tower mustard in the spotlight and working together at scale, we can demonstrate how to bring a rare London species back from the brink,” he said, as reported by London Now.⁶

The organizers hope the approach can travel. “We are hoping that this model can be used as a blueprint for helping other rare plants with volunteer input in the same way,” Harris said in the BBC report.¹ First, the new tower mustard has to settle in at its new sites.