What flowering plants for Texas inthe fall?

Winter annuals are the first choice. These are hardy enough to go through winter unscathed by freezing weather. Some, like violas and pansies, will bloom through winter. Others, such as snapdragons, will wait till early spring before blooming. Some will stay small and compact over winter, growing only once the weather begins to warm. This is how most of our wildflowers act, germinating in late fall and hugging the ground until spring.

Others are sweet allysum, sweet peas (not the vegetable), calendula (aka pot marigold), pinks and sweet Williams, larkspur, bachelor buttons (aka cornflower), stocks, and flowering cabbage and kale for colorful foliage.

Many of these are available at nurseries for fall planting. Unfortunately, many are also forced into bloom early. Cut back the flowers as they fade and the plants should bloom again. Some, like stocks, are difficult to find until spring. Consider trying to grow those unavailable at nurseries from seed. Lenten rose (aka winter rose) is a perennial that blooms late winter to early spring, but it prefers shade, a neutral pH and some lime in the soil. Winterglow bergenia is also a perennial that blooms in late winter to early spring.

HI Ths article will give you some suggestions https://www.hunker.com/12413940/fall-winter-flowers-in-north-texas