9 Flowers to Plant in June for Blooms all Summer

If you're looking at empty spots in your garden and thinking you've missed the boat on summer flowers, I have good news. June is actually an ideal time to sow many fast-growing annual flowers that will reward you with blooms from midsummer right through to frost.

The warm soil means super-fast germination, and these heat-lovers will quickly catch up to (and sometimes surpass) flowers planted earlier in the season.

The trick is choosing varieties that germinate quickly and bloom fast. You want flowers that can go from seed to bloom in 2 months or less, giving you plenty of time to enjoy them before fall arrives. Many of these quick growers also happen to be some of the easiest flowers to grow from seed, making them perfect for beginners.

Whether you're filling gaps left by spring bloomers, starting a cutting garden from scratch, or just realized you forgot to plant flowers this year (we've all been there), these June-sown beauties will save your summer garden.

Zinnias

If you only plant one flower from seed in June, make it zinnias. These June flowers absolutely thrive in heat and can go from seed to bloom in as little as 60 days. In fact, zinnias often perform better when sown in warm soil than those started indoors earlier in the season.

The 'California Giants Blend' offers those classic blooms in every color imaginable, growing 24-48 inches tall and perfect for cutting. If you prefer something more unique, try 'Queeny Lime Red' with its unusual green and rose coloring, or 'Zinderella' for frilly, scabiosa-like blooms that look nothing like typical zinnias.

Direct sow zinnia seeds about half an inch deep in well-draining soil. They'll germinate within a week in warm soil and start blooming about 8 weeks later. Just remember to sow them where you want them to grow, as zinnias hate being transplanted.

Sunflowers

Considering their ultimate size, sunflowers are practically magical in their speed of growth, making them perfect for June sowing. While you might not get those massive 10-foot giants when starting this late, plenty of varieties will give you gorgeous blooms in 60-70 days.

'Teddy Bear' is a great June flower, producing blooms in warm shades of gold on compact plants. For something different, try 'Vanilla Ice' with its pale cream petals and dark centers, or 'Moulin Rouge' for deep burgundy blooms that look stunning in arrangements.

Plant sunflower seeds directly in the ground about an inch deep. They need full sun (hence the name) and prefer soil that's not too rich, as excess nitrogen gives you huge leaves but fewer flowers. Thin seedlings based on mature size, and stake taller varieties if you're in a windy location.

Marigolds

Marigolds might seem basic compared to the previous two entries, but there's a reason they're garden staples. These reliable bloomers can flower in as little as 45 days from seed, making them ideal June flowers. Plus, they'll keep blooming until frost with minimal care.

French marigolds tend to bloom faster than African types, so stick with these for June planting. Sow seeds about half an inch deep, and thin seedlings to 6-8 inches apart for French types (10-12 inches for larger varieties). They'll tolerate poor soil but bloom best with regular deadheading.

The bonus with marigolds is their pest-deterrent properties. Plant them throughout your vegetable garden to help keep aphids and other unwanted visitors at bay while adding a pop of color.

Cosmos

Don't let their delicate appearance fool you. Cosmos are tough June flowers that thrive in heat and actually prefer poor soil. They're also incredibly fast-growing from seed, often blooming in just 7-8 weeks.

'Sensation Blend' gives you those classic pink, white, and magenta blooms on 4-foot plants, perfect for filling large spaces quickly. For something more unusual, 'Double Click' produces frilly, double flowers that look like mini dahlias.

The key with cosmos is not to worry about them. Rich soil and too much water lead to lots of leaves but few flowers. Scatter seeds on the surface (they need light to germinate) and barely cover. Thin to 12-18 inches apart and let them do their thing. They'll often self-sow for next year too, if you let some flowers go to seed.

Nasturtiums

Nasturtiums not only have beautiful blooms but edible flowers and leaves, too. Plus, they’re super easy to grow and quick to germinate. They'll start flowering about 35-50 days from seed, giving you plenty of summer color.

'Alaska' offers the bonus of variegated foliage that looks good even before flowering starts. 'Black Velvet' features deep crimson blooms against blue-green foliage for a sophisticated look.

Nasturtiums are another June flower that prefers poor soil. Rich conditions give you huge leaves that hide the flowers. Soak the large seeds overnight for faster germination, then plant half an inch deep. They can handle partial shade better than most summer flowers, making them useful for brightening up less-than-ideal spots.

Mexican Sunflowers

If your garden gets blazing hot in summer, tithonia (Mexican sunflower) is your answer. These vibrant June flowers don’t mind heat and drought, blooming about 60-70 days from seed and continuing until frost.

'Torch' is a classic variety, growing 4-6 feet tall with brilliant orange blooms that monarch butterflies adore. For smaller gardens, there are more compact options that stay around 30 inches but bloom just as prolifically.

These heat-lovers hate cool conditions but explode with growth once temperatures rise. Give them full sun and well-draining soil, then basically ignore them.

Celosia

For something different, celosia adds incredible texture to the summer garden. These heat-loving annuals come in various forms and can bloom in as little as 60 days from seed.

'Chief Red Flame' produces those classic cockscomb flowers in jewel tones, while 'Pampas Plume' offers plume types in brighter shades. For the cutting garden, 'Flamingo' provides pale pink spikes that look amazing fresh or dried.

Celosia needs warm soil to germinate well, making June perfect for direct sowing. Barely cover the tiny seeds and keep soil moist until germination. Once established, they're quite drought-tolerant and bloom more heavily when slightly stressed.

Coreopsis

While many think of coreopsis as a perennial, they can be treated as annual June flowers. They will reward you with cheerful blooms in about 55-65 days. These daisy-like flowers are practically indestructible once established and will bloom continuously until frost takes them down.

'Incredible!' lives up to its name with large blooms in shades of purple, pink, and white on compact 16-inch plants. 'Plains' varieties offer that classic yellow coreopsis look but with better heat tolerance than perennial types.

Direct sow these tiny seeds on the soil surface. Coreopsis tolerates poor soil and blooms better without heavy feeding. Once they start flowering, deadhead regularly or simply shear the whole plant back by one-third when blooming slows. They'll bounce back with fresh growth and flowers in just a couple of weeks.

Sweet Alyssum

Sweet alyssum might be tiny, but it's mighty when it comes to providing quick summer color. This fragrant annual can bloom in as little as 45 days from seed, a great June flower to use as an edging plant or to fill gaps between larger flowers.

'Tiny Tim' is a classic white variety that creates a foam of tiny flowers perfect for softening edges and filling containers. 'Allure Pastel Blend' adds purples, pinks, and roses to the mix if you want more color variety.

The secret to success with alyssum is understanding it prefers cooler conditions. In hot climates, it might slow flowering during the peak of summer, but it will come back as temperatures drop in early fall. Keep it well-watered during heat waves, and don't hesitate to give it a trim if it gets leggy. It'll quickly resprout and bloom again.