They are vital if you have fish in your pond as they add oxygen to the water. You can have deep marginals that happily sit in 15-30cm of water and shallow marginals – try Japanese iris, or bog plants ...

The pinkish-flowered plant, known as grass-poly, was found growing on the banks of an old farmland pond in Norfolk. The mystery species "came back from the dead" after seeds submerged in the mud ...