I've visited a couple of inner-London garden centres on this blog, each very different. If you're in the Portobello/ Westbourne Grove area, looking for a bit of respite from shopping and Notting Hillites with loud, intrusive voices, I can recommend taking a brisk 15 minute walk north-eastwards and heading under the Westway to Little Venice. (You could of course pick up one of the Barclays Bikes - but they weren't operating for casual use the day I went). Whichever means of transport you choose, when you get there, you can escape the crowds of tourists, sample a bit of waterside London (more Amsterdam, I always think than Venice), and stop for tea and cake at Clifton Nurseries.
It's easy to miss, especially at the moment with the entrance disguised by some of London's finest scaffolding. But dart down the alleyway behind two rows of houses and you'll find a gorgeous plant paradise. Stuffed with beautiful specimens (I had to tear myself away from an Angelica gigas, which the assistant told me does better in damp soil - it will never grow in my garden), and seductive garden accessories. It really doesn't feel like a garden centre and you can get quite lost in the aisles. I loved this large resin pot, embedded with small slices of pruned wood - what a great way to use up your trimmings.
I also liked the fact that the plants are labelled when British grown (it's good to see more garden centres doing this); and there are sections for plants to suit different areas of the garden. These are clearly signposted with advice and tips from local gardeners who open for the NGS - so you can visit a garden, see a plant you like, then pop round the corner to Clifton's to buy it. Very canny. But it is a great place for inspiration for the urban gardener, although a bit of a tease if you're on a budget - their price for a 20cm box ball is £24.95 (almost a tenner more than in less salubrious Hammersmith). And the lemon drizzle cake was not the best, but in such lovely surroundings, it was forgiveable.