Bridesmaid dress..

Hi ! I am getting married next October. I ordered my wedding dress, which is arriving November.
I asked my bridesmaids to start looking at what styles they would like etc but they would like to wait until next next year. But I don't know as well when it's the right time to purchase them ... in case we need to try different styles or exchange for different sizes and then Accessories and shoes etc. I wouldn't want to leave last minute and then flowers to go with dresses etc .

I am getting married next September and have my sister as a bridesmaid. We have bought her dress now so we can alter if needed and match accessories with the dress (we have not discussed this) and this should be ready for December. I do, however, think it depends on how many bridesmaids you have and if they are local or far away to when is best to look for dresses and if you want them to find their own dresses online or having matching ones as if they are buying online they can this nearer the wedding but if you want them all the same from a shop the sooner the better so they can order the dresses in and make adjustments if needed.