Depends upon the weeds. If you can get ahead of them before you broadcast your flower seeds, you have a fighting chance of keeping them at bay so the flowers can establish.
Cover the area with clear plastic and 'cook' it with sunlight for a few weeks before you plant? Start the seeds indoors so the flowers you want to grow will have a head start on the weeds. It's not exactly Mother Nature's way, but at least it's not weed killer and bedding plants from the store . . Once you plant the flowers, your hands are the only way to keep the weeds in control without risking the flowers.
