Depends if you mean Flowers or veg.

This link should help;

http://www.thegardenersalmanac.co.uk/Propagation/September.htm

sorry i ment vegatables and thank you
would i need a green house? or would they still grow if it snows a little or the grown freezes?

Your a bit late for Veg sowing, but you can plant out Japanese Onion sets and Garlic next month to be harvested next year!

Still time for some lettuce and radish though!

thanks i'll try them all but how do you do the garlic and japanese onion? do you just plant them next month and then let them grow till next year?
ps
thank you so so much your a great help thanks again

Japanese Onions like this;

http://www.thegardenersalmanac.co.uk/Data/Onions-Japanese/Onion%20-%20Japanese.htm

Garlic like this;

http://www.thegardenersalmanac.co.uk/Data/Garlic/Garlic.htm

thank you :)