12 Best Annual Flowers to Grow From Seed

By
Marie Iannotti
Garden Writer Marie Iannotti
Marie Iannotti
Marie Iannotti is a life-long gardener and a veteran Master Gardener with nearly three decades of experience. She's also an author of three gardening books, a plant photographer, public speaker, and a former Cornell Cooperative Extension Horticulture Educator. Marie's garden writing has been featured in newspapers and magazines nationwide and she has been interviewed for Martha Stewart Radio, National Public Radio, and numerous articles.
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Updated on 04/01/21
Red poppy flowers in middle of field with different wildflowers

The Spruce / Evgeniya Vlasova

You can grow a lovely flower garden simply by directly sowing seeds of annual flowers. Starting seeds in the garden is easy, though it does require some patience. You won't see many flowers for the first couple of months. But after they arrive, they often will bloom until frost hits. Unlike perennial flowers, which generally take two years to start blooming, annuals are quick growers and eager to get down to the business of blooming. Here are 12 of the easiest annual flowers to grow from seed.

Tip

It's highly cost-effective to grow flowers from seed, as you'll get more plants than if you purchased seedlings. Plus, depending on the conditions, some of these plants might reseed, giving you free plants for the next growing season.

12 Best Annuals for Full Sun
  • 01 of 12

    Bachelor's Button (Centaurea cyanus)

    A closeup of a cluster of cornflower
    Berndt Fischer/Oxford Scientific/Getty Images

    Although most Centaurea species are perennials, such as mountain bluet (Centaurea montana), the old-fashioned bachelor's button (also known as the cornflower) is an easy-growing annual. These flowers can be sown in early spring around your last frost date. The seeds like a chill, and the young seedlings can handle cooler temperatures. They take about 10 days to germinate and 50 to 60 days to bloom. You can reseed them in midsummer for a succession of blue blooms. Furthermore, bachelor's button attracts beneficial insects, including ladybugs and lacewings.

    • Color Varieties: Blue
    • Sun Exposure: Full sun
    • Soil Needs: Average, medium moisture, well-draining
  • 02 of 12

    Calendula (Calendula officinalis)

    Calendula flowers

    Araneel/Pixabay 

    Calendula, or pot marigold, is another lover of cool temperatures. Sow the seeds in the early spring right after your last frost date. They take approximately 10 days to germinate and 45 to bloom. These flowers are no relation to common marigolds (Tagetes sp.), though they are often yellow or orange and look vaguely similar. The flowers are edible with a citrus-like flavor. Older varieties are single flowered, but now there also are frilly double-flowered varieties. The singles seem to reseed more readily but not to the point of being a nuisance.

    • Color Varieties: Yellow, orange
    • Sun Exposure: Full sun to part shade
    • Soil Needs: Average, medium moisture, well-draining
  • 03 of 12

    Cosmos (Cosmos sp.)

    Cosmos flowers with light pink petals in middle and purple colored petals surrounding

    The Spruce / Evgeniya Vlasova

    You won't find an easier flower to grow from seed than cosmos. They will grow in the worst soils, springing up into tall, frilly plants with flowers ranging from pastel to neon colors. They take between three and 10 days to germinate and 70 to 84 days to bloom. Cosmos are quintessential cottage garden flowers and make themselves useful when scattered in the vegetable garden to attract pollinators. Sow the seeds once the soil has warmed a bit after your last frost date. Cosmos bipinnatus is the most commonly available species, with daisy-like blooms on branched stems.

    • Color Varieties: Yellow, white, pink, orange, red
    • Sun Exposure: Full sun
    • Soil Needs: Average, medium moisture, well-draining
  • 04 of 12

    Flax (Linum usitatissimum)

    A closeup of some blue flax flowers

    The Spruce / Marie Iannotti

    Besides patience, annual flax requires little effort on your part. It takes around 18 to 21 days to germinate and 50 to 60 days to bloom. Mark the planting area, so you don't accidentally plant something else where you've put its seeds. Sow the seeds after your last frost date. Flax plants can be floppy, so it helps to interplant them with sturdier flowers for support. Deadheading (removing spent flowers) will keep them blooming throughout the summer, and they will often reseed themselves.

    • Color Varieties: Blue, blue-violet, white
    • Sun Exposure: Full sun
    • Soil Needs: Fertile, medium moisture, well-draining
    Continue to 5 of 12 below.
  • 05 of 12

    Marigolds (Tagetes sp.)

    Close-Up Of Yellow Marigold Blooming Outdoors

    Siriwan Yothmontre/EyeEm/Getty Images

    Marigolds have become somewhat ubiquitous, and that should tell you something about how easy they are to grow. Their large seeds are easy to handle, and they are very reliable growers. Sow the seeds directly in your garden after all danger of frost has passed, or start them indoors four to six weeks prior to your last frost date. They take around four to 12 days to germinate and 60 to 70 days to bloom. Pinching off spent blooms from young plants can encourage them to bush out and set more flower buds.

    • Color Varieties: Yellow, orange, red
    • Sun Exposure: Full sun
    • Soil Needs: Average, medium moisture, well-draining
  • 06 of 12

    Morning Glory (Ipomoea purpurea)

    a closeup of some morning glories (Ipomoea tricolor)

    The Spruce / Marie Iannotti

    If you're seeking a fast-growing vine, look no further than morning glories. This flower doesn't transplant well, so seeds should be directly sown in your garden after your last frost date. The seeds have a hard outer covering that germinates faster if it's scarified (nicked or rubbed with sandpaper) and then soaked in water overnight. Germination can take around 10 days. Morning glories are late bloomers, often not flowering for around 100 days after they're planted. Some people refer to them as back-to-school flowers because they bloom in August.

    • Color Varieties: Violet and white
    • Sun Exposure: Full sun
    • Soil Needs: Average, medium moisture, well-draining
  • 07 of 12

    Nasturtium (Tropaeolum majus)

    Nasturtium flowers

    Laura Buttafoco/EyeEm/Getty Images

    The plump, round seeds of nasturtiums are easy to plant, germinating in around seven to 10 days. They tend to produce a mound of round leaves first and then nonstop bright, cheerful flowers after around 60 days. The whole plant is edible—even the seeds, which make great fake capers. Plant the seeds in your garden after the ground has had a chance to warm in the spring. Soaking and scarifying the seeds will improve germination.

    • Color Varieties: Red, orange, yellow, white
    • Sun Exposure: Full sun
    • Soil Needs: Average, slightly acidic, medium moisture, well-draining
  • 08 of 12

    Love-in-a-Mist (Nigella damascena)

    love-in-a-mist flowers

    Kevin Schafer/Getty Images

    Directly sowing love-in-a-mist plants in your garden is best. Plant them early in the spring by just sprinkling seed on the ground. They need light to germinate, so don't cover the seed with soil. It takes them around 10 to 15 days to germinate and 65 to 75 days to bloom. The plants tend to tire out, so reseeding monthly will extend their blooming period. With luck, some will reseed for you. The blooms work well as cut flowers, and the seed pods dry well for displays.

    • Color Varieties: Blue, white, pink, purple
    • Sun Exposure: Full sun
    • Soil Needs: Average, medium moisture, well-draining
    Continue to 9 of 12 below.
  • 09 of 12

    Poppies (Papaver sp.)

    Red poppy flower in front of field of other red and pink flowers

    The Spruce / Evgeniya Vlasova

    Poppy plants are worth growing just to watch the drooping buds burst open and raise their heads high. Annual poppies don't like being transplanted, so directly sowing in the garden is optimal. You can sow in early spring, even before the ground has thawed. The seeds need some light to germinate, so don't cover them. Just press down on the seeds for them to make good contact with the soil. They take about two weeks to germinate, but when the weather warms they will shoot up. Blooming occurs in around 65 days. After the seed pods dry, you can shake the flat-topped seed heads throughout the yard to reseed.

    • Color Varieties: Red, purple, pink, white, yellow, orange
    • Sun Exposure: Full sun
    • Soil Needs: Rich, medium moisture, well-draining
  • 10 of 12

    Sunflowers (Helianthus annuus)

    A closeup of a sunflower

    Dillemma Photography/Getty Images

    With sunflowers, you get to plant a seed and watch it grow 6 feet tall or more. Some of the tallest varieties produce only one flower, but it's usually a very large bloom. If you want more flowers, look for the branching varieties. Sow your seeds after the soil has warmed. They will take about two weeks to germinate and 75 to 100 days to bloom. Young seedlings often need protection from animals, such as birds. Plus, the taller varieties can get top heavy and might need staking. Deadheading the branching types will encourage more blooms.

    • Color Varieties: Yellow, red, copper, orange
    • Sun Exposure: Full sun
    • Soil Needs: Average, medium moisture, well-draining
  • 11 of 12

    Sweet Peas (Lathyrus odoratus)

    Closeup of a sweet pea flower

    Flavia Morlachetti/Getty Images

    Sweet peas like cool but not cold temperatures. Gardeners in areas where spring goes right into a tropical heat wave typically have the toughest time growing sweet peas, so they should consider starting them indoors a few weeks before their last frost. The seeds take around 10 to 28 days to germinate and 50 to 65 days to bloom. Scarifying and soaking the seeds before planting can speed growth. Also, deadheading the plants can help to prolong their blooming period.

    • Color Varieties: Pink, blue, red, purple, peach, white
    • Sun Exposure: Full sun
    • Soil Needs: Rich, medium moisture, well-draining
  • 12 of 12

    Zinnia (Zinnia sp.)

    Assortment of pink-shaded zinnias in a flower patch

    glennimage/Getty Images

    Colorful zinnias are one of the fastest-growing plants from seed. They are true annuals, not just tender perennials grown for a single season. They seem to know they only have a limited amount of time to grow, so they get to work quickly. Seeds take only around four to seven days to germinate and 50 to 55 days to bloom. Because they don't like being transplanted, directly sow them outdoors as soon as the soil has had a chance to dry out and warm up.

    • Color Varieties: Pink, red, purple, yellow, orange, white, green
    • Sun Exposure: Full sun
    • Soil Needs: Rich, medium moisture, well-draining