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 bloom from fall through spring.
1. Bachelor's Buttons, Cornflower (Centaurea cyanus)

Photo: © Marie Iannotti (2008) licensed to About.com, Inc.You won't often find Bachelor's Buttons at the nursery, but they grow very easily from seed and will reseed freely. A cottage garden plant, Bachelor's Buttons give its best display in cool seasons, so if you started some in the spring, watch as they perk up again this fall.

Marie IannottiCalendula looks like a fall flower, with its rich golden and rust colors. They might even withstand a light frost, if they're established. Many calendula will self-seed and treat you to a spring bloom as well.
3. Diascia

All America SelectionsDiascia though relatively new in gardens, became popular quickly. The tiny, profuse trailing blossoms make it perfect for containers. Diascia is generally grown from cuttings, which can make it an expensive annual. But you may be able to oover winteryours indoors or take your own cuttings. Diascia are perennial, with a good winter, in Zone 8 or higher.
4. Larkspur

Photo: © Stephanie Summerfield / Stock.xchng. Used with Permission.Where summers are too extreme to grow delphiniums, larkspur makes an eeminentlyacceptable 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.
5. Lobelia

Photo: © Marie Iannotti (2008) licensed to About.com, Inc.Lobelia will give out on you during the summer. But given cool temperatures, it will bloom with pprofusion If you planted yours in the spring, once the flowers start to slow down, cut it back a half and allow it to regrow and rebloom.

Photo: © Marie Iannotti (2008) licensed to About.com, Inc.Nasturtium will bloom throughout summer, 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.
7. Nierembergia

Photo: © All America Selections. Used with Permission.Nierembergia 'Mont Blanc' rescued nierembergia from oobsolescence Nierembergia is hardy to Zone 7 and can even be over wintered indoors, but you might not bother because it is fairly easy to grow from seed. 'Mont Blanc' won the AAllAmerica Selection award, but the blue flowered varieties are getting the attention now.

Photo Courtesy of All America SelectionsGardeners think of petunias as a bedding mainstay. Petunias actually do their best blooming in cool temperatures and there are so many to choose from. The Wave series has become especially popular and if you, like me, don't like deadheading, Wave petunias are for you. The tiny calibrachoa petunia make a nice textural accent in containers.
9. Snapdragon

Photo: © Marie Iannotti (2008) licensed to About.com, Inc.Snapdragons offer you 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 Zone 8. With some protection, they may also survive in Zone 7.

Photo Courtesy of the National Garden Bureau - www.ngb.orgYou 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.