I'm having to post via the dreaded Garden Banter (can't be arsed to sort out a Usenet provider and am still looking for a sensible and viable ISP [Wanadoo is the pits!!!]- nuff of that) so I'm not sure how many replies you've had. If you live within the Greater London conurbation, along sheltered parts of the south coast or in the far south west, you can successfully grow avocados to near tree-like proportions if you can provide wind shelter. As a 3-5 foot high, spindly 'twig' in a pot, it is a very dull plant indeed. Grown to a few to several metres high and across, it makes a very impressive shrub or tree with fine foliage.

It does produce in the UK and if you are geographically fortunate, you may even pick a moderate crop of palatable fruits after a decent summer. They will not be as large as those in the shops, but be grateful - this is England and they normally do their stuff in far warmer places. If you are so inclined, grow your seedling on for a year, keep it frost free next winter and plant it out during late May in a sunny corner. Nay-sayers may think otherwise, but I rate it quite highly, but only for the south.