It is probably either too late OR too early for seeding snapdragons. Mine are in full bloom planted where they get very little sun. In another month or more I will plant another batch to grow over the winter here. Your climate I feel sure will vary from mine. Al

Would it be a good idea to grow them during winter indoors? Or should I wait until next season?

I start my snaps seed in January, in the greenhouse, for spring flowering before weather gets too hot for them. Most of mine I will set out as four inch pot size in October for a whole winter of blooming. Winter temps here are seldom below 25 degrees. Al