There are many flowers that can be planted in October, including both annuals and perennials. Some of the best options include:

• Dahlias: These colorful flowers bloom around September and October and can continue into late autumn.
• Mums: These popular flowers come in a variety of colors and can bloom from mid-summer into fall.
• Pansies: These flowers can bloom from mid-summer and continue into late autumn.
• Sedum: This plant is a favorite for both humans and birds, butterflies, and hummingbirds. It blooms in the fall and is a great option for the autumn garden.
• Sunflowers: These bright yellow flowers can bloom around September and October.
• Crocus: These flowers can be planted in clusters in well-draining soil around 6 to 8 weeks before the first hard frost of the season.
• Tulips: These spring-blooming bulbs can be planted in the fall and will bloom in the spring.
• Peas: These vegetables can be planted in the fall and will bloom in the spring.
• Anemone: These daisy-shaped flowers come in a variety of colors and can be planted alongside other spring-flowering bulbs like daffodils, tulips, or hyacinths.
• Violas: These flowers can bloom in the fall and are a great option for autumnal container planting.
• Shallots: These vegetables can be planted in the fall and will be ready to harvest in the spring.
• Goldenrod: This fall-blooming perennial can add to the mix of other fall-blooming perennials like autumn joy sedum.
• Coreopsis: This easy-care plant blooms from spring to fall and can attract butterflies and birds to your garden.

Its important to check each plants sun and water needs and to consider fall flowers that attract bees and other pollinators. Additionally, its pertinent to check your USDA hardiness zone to determine which plants will thrive best in your area.