10 Best Annual Flowers for the Cool Season

Cool weather can be hard to garden in because you never know how long it will last. But there are many garden flowers that prefer the cool days of spring and fall. Often, gardeners think only of perennials for a sequence of bloom. Many cool-season annuals look wonderful in containers and growing these flowers will make your gardening season seem that much longer. If you live in a warm climate, some of these flowers will be perennial for you and will bloom from fall through spring.

Extend your gardening season by adding one of these 10 cool-season annual flowering plants to your garden.

  • 01 of 10

    Bachelor's Buttons, Cornflower (Centaurea cyanus)

    Bachelor Buttons

    Marie iannotti

    You won't often find bachelor's buttons at the nursery, but they grow easily if directly sown in the garden and will reseed freely. A cottage garden plant, bachelor's buttons give their best display in cool seasons, so if you started some in the spring, watch as they perk up again in the fall.

    • USDA Zones: 2 to 11
    • Color Varieties: Blue, purple, pink, and white
    • Sun Exposure: Partial to full sun
    • Soil Needs: Well-draining, alkaline soil
  • 02 of 10

    Calendula, Pot Marigold (Calendula officinalis)

    A marigold (Calendula Officinalis)
    StockFood / Getty Images

    Calendula, or pot marigolds, look like fall flowers, with their rich golden and rust colors, and they do best later in the season. They might even withstand a light frost if they're established. Many calendulas will self-seed and treat you to a spring bloom as well. Calendula is an edible flower and is popular for planting in an herb or vegetable garden.

    • USDA Zones: 9 to 11
    • Color Varieties: Bright yellow to deep orange, creams, and pinks
    • Sun Exposure: Full sun to partial shade
    • Soil Needs: Average, well-drained soil rich in organic material
  • 03 of 10

    Diascia

    Potted diascia (Diascia) 'Red Miracle'
    Gert Tabak The Netherlands / Getty Images

    Diascia, though relatively new in gardens, quickly became popular. The tiny, profuse trailing blossoms make it perfect for containers. Diascia is generally grown from cuttings, which can make it an expensive annual to purchase. But you may be able to overwinter yours indoors or take your own cuttings. Diascia is perennial, with a good winter, in USDA Zone 9 or higher.

    • USDA Zones: 9 to 11
    • Color Varieties: Pink, white, coral, orange, red, and plum
    • Sun Exposure: Partial to full sun
    • Soil Needs: Fertile, well-drained soil
  • 04 of 10

    Annual Larkspur (Consolida ajacis)

    Pink Larkspur
    Gary J Weathers / Getty Images

    Where summers are too extreme to grow delphiniums, larkspur makes an eminently acceptable substitute. If you start your larkspur off in the spring and keep it deadheaded throughout the summer, a little extra food should revive it for the fall show. These make excellent cut flowers.

    • USDA Zones: 2 to 10
    • Color Varieties: Purple, pink, white, and blue
    • Sun Exposure: Full sun to partial shade
    • Soil Needs: Slightly moist to dry, well-drained soil
    Continue to 5 of 10 below.
  • 05 of 10

    Lobelia (Campanulaceae)

    Blue Lobelia
    Paul Tomlins / Flowerphotos / Getty Images

    Lobelia will shut down during the summer, but given cool temperatures, it will bloom with profusion. If you planted yours in the spring, once the flowers start to slow down, cut it back by half and allow it to regrow and rebloom.

    • USDA Zones: 10 to 11
    • Color Varieties: White, blue, purple, lilac-pink, and cherry-red
    • Sun Exposure: Full sun to partial shade
    • Soil Needs: Evenly moist and well-drained soil
  • 06 of 10

    Nasturtium (Tropaeolum spp.)

    Nasturtium Flowers
    Laura Buttafoco / EyeEm / Getty Images

    Nasturtiums will bloom throughout summer and well into fall. They are rejuvenated by the cooler air. Even their crisp fall colors advertise that they belong in the fall garden. Nasturtiums don't transplant well and you may be better off direct seeding. Keep them well watered in the heat of summer. They have large seed pods that are easy to collect and save to replant next season.

    • USDA Zones: 2 to 11
    • Color Varieties: Red, orange, pink, yellow, and cream
    • Sun Exposure: Full sun
    • Soil Needs: Evenly moist and well-drained soil
  • 07 of 10

    Nierembergia 'Mont Blanc'

    nierembergia rivularis, september
    Sunniva Harte / Getty Images

    The Nierembergia 'Mont Blanc' variety rescued nierembergia from obsolescence. Nierembergia is hardy to USDA Zone 10 and can even be overwintered indoors, but you might not bother because it is fairly easy to grow from seed. 'Mont Blanc' won the All America Selection award, but the blue-flowered varieties are rising in popularity.

    • USDA Zones: 7 to 10
    • Color Varieties: Blue, purple, and white
    • Sun Exposure: Full sun to partial shade
    • Soil Needs: Sandy, silt, loamy soil
  • 08 of 10

    Petunia (Petunia x hybrida)

    Purple Wave Petunia
    Purple Wave Petunia Ron Evans / Getty Images

    Gardeners think of petunias as a bedding mainstay, and the flowers actually bloom best in cool temperatures. The Wave series has become especially popular and if you don't like deadheading, Wave petunias are for you. The tiny calibrachoa petunia makes a nice textural accent in containers.

    • USDA Zones: 8 to 11
    • Color Varieties: Various, including pink, purple, and yellow
    • Sun Exposure: Full sun
    • Soil Needs: Well-draining, clay, or sandy soil
    Continue to 9 of 10 below.
  • 09 of 10

    Snapdragon (Antirrhinum majus)

    Snapdragon Flowers
    Snapdragon Flowers

    Marie Iannotti

    Snapdragons offer color and a bit of height, depending on the variety. There are also new trailing snapdragons that work wonderfully in containers. Look for the Luminaire series. Snapdragons are hardy at least to USDA Zone 8. With some protection, they may also survive in Zone 7.

    • USDA Zones: 7 to 10
    • Color Varieties: White, yellow, pink, red, orange, peach, purple, and violet
    • Sun Exposure: Full sun to partial shade
    • Soil Needs: Well-draining, rich, moist soil
  • 10 of 10

    Viola, Pansy (Violaceae)

    Light Blue Pansy Flowers
    Andy Muskopf / Getty Images

    You may still have some pansies from last spring languishing in your garden beds. Look around and see if they are perking up for fall. Violas and pansies will bloom for weeks. Deadheading will keep them setting new buds. Look for some of the newer varieties that can handle a slight freeze.

    • USDA Zones: 3 to 8
    • Color Varieties: Light to deep violet, white, blue, yellow, cream, and multi-colors
    • Sun Exposure: Full sun
    • Soil Needs: Well-draining, rich, moist soil