The final Sunday in a new nationwide festival, a collaboration between the Society of Garden Designers and the RHS, sees two private gardens in London open to the public. Charles Rutherfoord's plantsman's garden in Clapham (51 The Chase, SW4 0NP; open noon-4pm) is hidden behind a pierced wall of railway sleepers covered in roses. It features a geodetic dome where seedlings, succulents and subtropical plants are grown. Emma Plunkett's garden in Shepherd's Bush (49 Loftus Rd, W12 7EH; open noon-4pme) operates as both a showcase and a laboratory. The narrow, west-facing walled garden backs onto an orchard and is organised around a central path with fruit, vegetables and herbs growing in on either side in a cold frame and raised beds.See the website for full details.