Plant These Now: 10 Full-Sun Annuals That Bloom Fast

If you garden in an area that is buried under snow or held captive by below-freezing temperatures for weeks (or months!), the wait for spring can often feel endless. Especially when there are so many fabulous annuals that need consistently warm weather to thrive. Read on for a list of sun-loving annuals you can plant once the risk of frost has passed.

Not sure when the last frost date for your region is? Check the trusty Farmer's Almanac. Even still, climate change is making it harder to predict exactly when warm weather will arrive and frequently, gardeners are thrown a rogue late-spring frost or two. Mother's Day is often used as a safe threshold for planting annuals, but it's not a very reliable method.

If you live in a cold climate, you may have to wait another couple of weeks, until closer to Memorial Day. Alternatively, you can start your annuals indoors and have seedlings ready for transplanting when the weather's right.

1. Ageratum

Underrated and often overlooked at the garden center, ageratum is a tidy annual featuring fuzzy, button-shaped flowers. Don't let the cute blooms fool you though-ageratum is heat-tolerant and quite hardy. A few taller cultivars, like ‘Red Flint' and ‘Blue Planet', make excellent cut flowers; however, the majority of ageratum cultivars are compact bedding plants.

Plant ageratum in well-drained soil and full sun. Transplant seedlings or sow seeds directly in the soil once the last frost date has passed. Water ageratum regularly, especially during the hottest weeks of the summer.

2. Calendula

Cheery calendula is prized as a cut flower, edible, medicinal herb and dye plant. Calendula's daisy-like blooms are traditionally available in bold orange and yellow, but plant breeders have produced cream, apricot, blush pink, copper and burgundy cultivars. This hardy annual matures quickly, going from seed to flower in as few as 50 days, and grows happily in full sun.

Calendula flowers best in average soil with little to no fertilizer and will reseed enthusiastically if not harvested or deadheaded. Plant seeds right around the last frost date.

3. Cosmos

Cosmos are adored for their airy blooms and carefree nature. They grow best in average, well-drained garden soil and in full sun. Seeds can be started indoors four to six weeks before the last frost date, or sown directly outside soon after the last frost.

Cosmos work beautifully in meadowscapes, pollinator gardens, along fencelines and in other informal cottage gardens. Despite the delicate appearance of their petals, cosmos are also excellent cut flowers; harvest stems when buds are fully colored and just starting to unfurl. Try the iridescent peach ‘Apricotta', the cranberry-hued ‘Rubenza' or the ultra-ruffled ‘Double Click' series.

4. Geraniums

Geraniums have been gracing our grandma's window boxes for decades. Heat-loving, fragrant, and oh-so-tolerant of neglect, these are mounding or trailing tender perennials typically grown as annuals. These plants thrive in full sun: they really cannot get enough of it!

Clusters of flowers in red, hot pink, coral and bicolor flowers rise up from fuzzy leaves on sturdy stems. Regular deadheading will encourage a tidy look and continuous new blooms. Seedlings can be started indoors six to eight weeks in advance and planted outside just after the risk of frost has passed, but most gardeners prefer to purchase plug plants or get cuttings from neighbors.

A quick botany lesson: The flowering annual we know and love is actually a type of pelargonium, although many nurseries and big box stores still refer to them as geraniums. True geraniums are a group of cold-hardy perennials commonly called cranesbill.

5. Lobelia

Lobelia is a low-growing flowering annual prized for its tiny, tubular blooms in icy-cool shades of white, lavender, periwinkle and deep indigo. This plant's fine leaves and mounded, bushy habit make it perfect in containers, hanging baskets and along the front of walkways and edging. Plant lobelia in full sun, in rich, fertile soil. This annual prefers mild temperatures and may put flowering on pause during the hottest weeks of the year.

Don't confuse annual lobelia with perennial types, like the spiky red cardinal flower (Lobelia cardinalis) or great blue lobelia (Lobelia siphilitica). The latter are two native species found in woodlands and wet meadows throughout zones 4-9.

6. Morning Glory

Known for their showy, funnel-shaped flowers that open early in the day, morning glories are a much-loved garden classic. Elegant blooms in shades of blue, purple, rich red and pale rose appear from the start of summer until the first hard frost. Morning glories tolerate partial shade but will bloom most profusely in full sun. These vining annuals can easily grow several feet long and greatly benefit from a trellis, arbor, fence,or other sturdy support.

Plant morning glories a week or so after the last frost date of the season. Morning glory seeds have a particularly tough seed coat. For the best germination rates, soak seeds overnight just prior to planting. The royal purple heirloom variety ‘Grandpa Ott' is a personal favorite.

7. Nasturtium

With their edible flowers and unique lily pad-shaped leaves, nasturtiums are charming additions to the garden. Nasturtium's cascading growth habit lends itself well to planters, hanging baskets and other containers. Flowers are most commonly bright orange; however, yellow, cream, maroon and bicolor cultivars are growing rapidly in popularity.

Plant nasturtium in full sun and average soil. As with calendula, overly fertile soil or too much nitrogen-heavy fertilizer can result in nasturtium with tons of leaves and few flowers. Nasturtiums don't like their roots disturbed. Because of this, sow seeds directly in the garden bed as soon as the last frost date has passed.

8. Nicotiana

Nicotiana's nodding, star-shaped flowers, which are usually white, pink, violet or red, are pollinator magnets and highly attractive to hummingbirds and moths. Many varieties are sweetly fragrant. Also known as flowering tobacco, nicotiana thrives in heat and full sun.

Nicotiana seeds or seedlings can go into the garden immediately after the last frost. This fragrant flowering annual grows easily in average garden soil. Pair nicotiana with a mix of other tall, sun-loving plants like cosmos, asters and bee balm, for a colorful pollinator bed.

9. Sunflower

Nothing screams summer like a row of brilliant sunflowers! Plant sunflowers in full sun, in well-drained, loose soil. Sow seeds directly in the garden just after the last frost date has passed. Planning to grow sunflowers as a cut flower? Succession sow these beauties every two weeks to enjoy a continuous harvest well into the fall. Harvest stems when the petals are just starting to lift away from the center seedhead or leave the plants for birds to enjoy.

If you're seeking a variety beyond the traditional solid yellow, try brown-striped bicolor 'Ziggy' or ruby-red ‘Moulin Rouge'.

Zinnia

Low-maintenance zinnias are easy additions to the garden. Zinnias are available in a full rainbow of colors, from lime green and neon orange to soft peach and rich wine-red. There is almost certainly a zinnia cultivar for every patch of your garden. Try compact ‘Profusion Cherry Bicolor' in your patio planter and the uber-tall ‘Benary's Giant' mix in your cutting garden or along a bare fenceline.

Plant zinnias in full sun after all risk of frost has passed; this frost-tender annual loves the heat and germinates best once soils have warmed. Zinnias grow easily in average soil and rarely need fertilizer to keep blooming right into fall.

Related: 22 Best Flowers for Shade

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This story was originally published May 6, 2026 at 5:15 AM.