You must be mindful of the fluctuating temperatures when planning your fall flowers. If you plant too early and it gets to hot outside you will loose some of your plants. It you wait too late the cold temps will keep the plants from rooting and doing as well. Snapdragons are tender perennials that will repeat bloom throughout the season but do best in the cool of spring and fall. Throughout the winter their performance will depend on how extreme our weather is. The colder it is the less they will bloom. Don’t count them out in the Spring time. As it warms up they will explode and often still be blooming when it is time to plant your summer flowers. Hope this helps!