I am getting married in August and I just started meeting with florists. I have been told not more than a year out. In regards to cake, most places advise 2-6 months out from the wedding.
I was very bad I didn't book until I was about 1 month away. We had such a low key wedding, and I took my time booking. You really should start looking about 1 year out the popular vendors book up quick.
I booked both my florist and cake about 10 months in advance. I would highly recommend my florist - Kristin at Local Color Floral and my baker - Shara at Chickadee Hill Cakes. Both wonderful people and reasonably priced.
I've already booked my cake, but I was trying to get things done before I left for school. My uncle is doing my flowers and I've been in touch with him already.
We booked our cake a few months back and will be sending in our deposit on flowers in the next week when we get the contract in the mail. I would think that since your getting married in a popular month it might be good to book them soon!
April 2010 January SC - Favorite Picture from the Holidays
DH & I at the Light Festival
Re: Flowers and cake question
DH & I at the Light Festival