10 Best Fast-Growing Flowers to Plant in June, Say Experts

Whether time got away from you this spring and you didn't have a chance to start your flower garden, or if you have bare spaces in your plantings you want to fill, June is still a great time to get plants in the ground. To do so successfully, you must find varieties that can withstand getting established in the warmer temperatures and longer days June provides. To help, we spoke to gardening experts who shared the best fast-growing flowers to plant this month.

Jennifer Petritz, horticulturist, garden coach, and horticultural consultant specializing in small garden design
Angela Judd, certified master gardener and author of How to Grow Your Own Food

01 of 10

Spider Flower

As the name suggests, the blossoms of spider flowers (Cleome) have long "legs" attached to a central body, resembling spiders. "Fast-growing spider flower is perfect when you need a tall-growing wispy plant to add to your summer borders," says horticulturist Jennifer Petritz, who especially likes the Queen series. "It's really lovely, I’m partial to 'Violet Queen,'" she says. "Seeds germinate quickly in warm temperatures. Sow in June and you’ll have flowers by August."

Zones: 2 to 11
Size: 4 to 6 feet tall x 3 to 5 feet wide
Care requirements: Full sun; moist, well-drained soil

02 of 10

Mexican Sunflower

A favorite of pollinators, the Mexican sunflower (Tithonia rotundifolia) is a stunning addition to the summer garden. "Mexican sunflower is like a shot of Vitamin C for a summer flower border," says Petritz. "Seeds germinate rapidly in warm conditions and full sun. Tithonia’s warm orange is great for mixing with blue salvias for a late summer flower show." She also notes that it makes an excellent cut flower.

Zones: 2 to 11
Size: 3 to 6 feet tall x 2 to 3 feet wide
Care requirements: Full sun; well-drained soil

03 of 10

African Marigold

For an especially speedy flower, Petritz recommends the 'Kilimanjaro White' variety of African marigold (Tagetes erecta). "African marigold is a quick and easy plant to incorporate into a summer garden," she says. These marigolds are a little taller with giant, creamy white powder puff flowers that go beautifully with any other color. African marigold germinates in five days and can be planted in succession for continual blooms through frost, she says.

Zones: 2 to 11
Size: 1 to 4 feet tall x 1 to 2 feet wide
Care requirements: Full sun to partial shade; well-drained soil

04 of 10

Zinnia

The incredibly vibrant colors and spherical, ruffled shape of zinnias (Zinnia spp.) will dazzle any garden visitor. Zinnias are quick-growing flowers that will rapidly add color to your landscape. "From simple to fancy, there's a zinnia for every taste," says master gardener Angela Judd. "The more you cut, the more they bloom."

Zones: 3 to 10
Size: 14 to 18 inches tall x 20 to 24 inches wide
Care requirements: Full soil, well-drained soil

05 of 10

Sunflower

Despite their massive height, sunflowers (Helianthus) are another excellent option for rapid blooms. The variety you choose to plant will depend on your sunflower growing goals. "Choose mammoth types for seeds or branching types for blooms and shade," says Judd. Maturing times vary, but you can find some sunflowers that mature in around 50 days.

Zones: 3 to 9
Size: 1 to 10 feet tall x 1 to 3 feet wide
Care requirements: Full sun; sandy or loam, well-drained soil

06 of 10

Nasturtium

The bell-like blossoms of nasturtiums (Tropaeolum) come in various bright colors, from delicate yellows to vibrant oranges. These flowers are a hero in the garden—not only are they fast-growing, but they also repel pests, making them an incredible companion plant. Some types are climbers and will delicately scale a trellis, decorating it with a fun burst of color.

Zones: 2 to 9
Size: 1 to 10 feet tall x 1 to 3 feet wide
Care requirements: Full sun; well-drained soil

07 of 10

Calendula

Blooming in lovely autumn-inspired shades of gold, orange, white, and tan, calendula (Calendula officinalis) is a member of the daisy family. Some varieties of this charming, fast-growing plant mature in as little as 50 days. Calendula will keep blooming until the first frost if you stay on top of deadheading.

Zones: 2 to 11
Size: 1 to 2 feet tall x 1 to 2 feet wide
Care requirements: Full sun; well-drained soil

08 of 10

Bachelor's Button

Another member of the daisy family, but with petite, round blossoms and plenty of attractive foliage, bachelor's button (Centaurea cyanus) yields blue-purple flowers that fill the garden with color and charm in no time.

Zones: 2 to 11
Size: 2 to 3 feet tall x 1 to 2 feet wide
Care requirements: Full to partial sun; sandy, well-drained soil

09 of 10

Cosmos

At first, it seems like cosmos (Cosmos bipinnatus) only put out large amounts of fern-like foliage. But just when you think nothing more will happen, their beautiful daisy-like flowers arrive in a rainbow of colors, all with fabulously impressive petals. They're one of Judd's go-to fast-growing flower options because they grow quickly and spread if you let them.

Zones: 2 to 11
Size: 2 to 4 feet tall x 2 to 3 feet wide
Care requirements: Full sun; well-drained soil

10 of 10

Tickseed

There are many cultivars of tickseed (Coreopsis) to choose from, and many are known for being fast-growing and low-maintenance. Tickseed quickly fills the garden with shades of yellow and orange (and sometimes shades of red and purple) and is a reliable choice for great garden color.

Zones: 4 to 9
Size: 6 inches to 4 feet tall x 1 to 2 feet wide
Care requirements: Full sun; well-drained soil