New covent Garden for sure. Worth getting up early for (go before 7am, the earlier the better). Maybe do couple of research trips to local florists to find out what varieties you'd like as just asking for 'pink' or 'white' will make you look like you dont know what you're doing. Ask around and don't forget to add the VAT! I don't rate columbia road. Old tatty flowers at bad prices, but yes, cheaper than a florist although I've never met a proper florist who would buy from there. One for the hipsters only. Great for plants though. I am a florist, by the way.