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What Flowers to Plant in March?

By MelissaBielawski ; Updated September 21, 2017
Dahlias can be planted in March.
dahlia image by Timothy Lubcke from Fotolia.com

Spring is a time of an abundance of blooming flowers. While the majority of spring-blooming flowers are usually planted earlier in the year and begin to blossom in the warmer weather, a handful of flowers can actually be planted in March in a few select regions once the threat of frost has passed. Typically, the very best areas for March planting are Southern California, Texas and Florida.


Cosmos (Cosmos bipinnatus) can be planted in March once the danger of frost has passed. Cosmos blooms large, showy flowers that, depending on the species, grow from 2-to-4 inches in diameter, with the plant itself often reaching more than 6 feet in height. Because of its height, cosmos typically needs stakes to hold it upright. Cosmos blossoms in a wide array of colors, including yellow, white, pink, orange and red. If dead flowers are removed, cosmos will bloom continually throughout the summer, according to the website Floridata. Once established, cosmos flourishes quickly with little care and actually requires minimal fertilization, since over-fertilizing can cause a decrease in blooms. This nectar-filled flower attracts an abundance of butterflies, and pretty blossoms make it a popular choice for cut flowers. Cosmos is hardy USDA planting zones 5 to 10 but can be planted in March in Southern California, Texas and Florida. Cosmos thrives in full sunlight with moist, well-drained soil.


Dahlias (Dahlia) can be planted in March once the chance of frost has passed and the ground has begun to warm up. Dahlias grow best in sunny conditions with moist, well-drained soil. Excessive moisture should be avoided since this can result in root rot. Because of their short root system, dahlias should be adequately protected from strong winds, which can cause the plants to be blown away, according to the website J.R.G Dahlias. Once established, dahlias grow easily with a minimum amount of care, reaching between 20 and 30 inches in height. Dahlias begin to bloom at the end of July and continue to produce flowers until the first frost. Along with white, dahlias bloom in a variety of warm-colored flowers, including red, yellow, pink and orange. To promote larger flowers, all side buds should be removed during the plant's flowering season. Dahlias will bloom continuously if all dead flowers are promptly detached. Depending on the cultivar, dahlia growth ranges greatly, from as small as 1 foot to more than 8 feet in height. Dahlias are hardy in zones 7 to 11, but can be planted in March in warmer southern states, including Texas, Florida and California.


Zinnias (Zinnia elegans) can be planted in March once the air has warmed and all danger of frost has ended. Blooming begins in the summer and continues into the fall until the arrival of the first frost. Zinnias produce a varied selection of brightly colored flowers, including yellow, orange, red, rose, pink and purple. Zinnias flourish in at least six full hours of sun per day, although in extremely hot areas, a few hours of shade in the afternoon is preferable. While zinnias are relatively hardy and can tolerate most soil conditions, they grow best in moist, well-drained soil, according to the website National Garden Bureau. When watering, it is best to wet only the roots and keep the foliage as dry as possible, as zinnias are susceptible to fungal diseases. Zinnias live up to a week once cut, and their longevity, as well as attractive stems, makes them an ideal fresh flower choice. Zinnias are hardy in USDA planting zones 3 to 10 but can be planted in March in Southern California, Texas and Florida.