7 fast-growing annual flowers to sow in June that will give you glorious summer displays in borders or containers

If you want some fast-growing flowers to add bright color and interest to flower borders this summer, it is not too late. June is an excellent time to sow lots of annual flower seeds that can germinate quickly and reward you with bountiful blooms for late summer.

The likes of cosmos, zinnia, sunflowers, calendula, bachelor’s button and more are all suitable for sowing this month. Plant these fast-growing flowering annuals this month, and your beds or containers can be awash with color, texture, and wildlife to enjoy within a matter of weeks.

If you are looking for annual flowers that germinate fast, grow quickly, and require little maintenance, this guide reveals seven fast-growing annual flowers to sow in June, along with some sowing and maintenance tips so you have happy plants and top displays.

Annual flowers to sow in June

These seven annual flowers to sow in June can all be sown directly into the soil this month and are known to develop rapidly. Whether you are looking for fast-growing annuals for flower beds or container gardens, these are all worth considering:

Bachelor’s button

These delicate flowers, also known as cornflowers, are one of the easiest flowers to grow from seed. Bachelor’s button germinates very quickly and goes from sowing to flowering in only a couple of months.

The small blooms sit atop thin stems and make great cut flowers with a long vase life.

Most people picture the classic blue bachelor’s button flowers; however, different varieties offer blooms in shades of red, pink, or white. Or, get a mixed pack like these mixed colors Bachelors Buttons Seeds at True Leaf Market for blooms in a range of different colors.

The flowers always grow best by sowing them directly into a growing position where they get at least six hours of sunlight each day. Sow the seeds thinly and cover with a light layer of soil.

Keep moist, and the seeds will germinate within two weeks. The bright, sweet blooms should follow around six weeks later.

Butter Daisy

Melampodium, or butter daisy, is an easy-to-grow annual from Central and South America that takes around 60 days from sowing to blooming.

Butter daisy plants reach two feet high and wide and bloom in shades of yellow or orange, depending on the variety. The bright flowers stand out along with the bright green foliage.

Melampodium thrives growing in a sunny spot that gets 6-8 hours of daily sunlight and has well-draining soil. Seeds can be sown directly into the soil or a container once the risk of frost has passed, covering them thinly with soil and keeping them moist.

The seedlings should appear within a couple of weeks and should be thinned to 12-18 inches apart for good air circulation.

Once butter daisy plants start blooming, they will keep on going without the need for deadheading, as they are self-cleaning plants that shed spent blooms themselves without the need for gardeners to pay extra attention.

Calendula

These bright annuals are renowned for germinating quickly, within a week, and sowing them this month will provide gorgeous late summer flowers in beds or containers, as it normally takes around 8-10 weeks to go from germinating to flowering.

Sow seeds outdoors this month by pressing the distinctive, curved seeds into the ground and covering with a thin layer of soil. Depending on which calendula varieties you grow and when you sow this month, you should expect vivid blooms in shades of orange, yellow, or white in August and September.

For a mix of colors, this pack of Pacific Beauty Mix Calendula Seeds from Amazon produces blooms in various shades of yellow and orange.

Not only are calendula stunning, but they are practical, too. They are great for companion planting and protecting vegetables from pests, while the plants produce edible flowers that can also be harvested for medicinal purposes.

California poppy

The California poppy is a wildflower native to California, and the bright flower is a fast-growing annual in summer. Typically bright orange in color, different varieties produce stunning blooms in pink, red, yellow, and white.

The vivid plants can bloom within eight weeks from sowing seeds directly into flower beds or borders. The seeds can be sown from April up until the end of June for a long and glorious flowering display.

This is a tough type of poppy that will grow even in poor soils and is drought-tolerant, meaning it won’t need lots of watering. Low-maintenance and quick flowering – what is not to love about growing California poppies?

The plants will perform best in full sun and well-drained soil. And, once established, California poppies are known to self-seed around a garden.

This packet of Sunset Mixed California Poppy Seeds at Walmart will grow plants with blooms in shades of red, cream, orange, and pink.

Cosmos

Cosmos are always a fantastic addition to any flower bed, as plants provide abundant color and texture to a space. With different types of cosmos available in anything from pastel pinks to vivid reds to multi-color blooms, there is a great range to pick from to suit any desires.

If you can't settle on just one color, this packet of Sensation Mix Cosmos Seeds from Burpee produces plants with red, pink, and white blooms for a stunning display.

Grow cosmos in a sunny and protected spot, with well-draining soil. If you plant cosmos seeds directly into their growing spot in June, they may potentially start to bloom within eight weeks.

But what about upkeep? Cosmos do benefit from watering and need supports to keep plants upright all summer long, which is especially vital for taller varieties. Regular deadheading is advisable to keep cosmos blooming as long into fall as possible.

Sunflower

One of the easiest annuals to grow from seed, there is a dazzling array of sunflower varieties you can grow. Plant sunflower seeds in June, and you can get blooms in 50-100 days, depending on the variety.

If you want super-speedy blooms, plant seeds of the ‘Jua Maya Hybrid’ Sunflower at Burpee that can go from sowing to flowering in 45-50 days.

Most people will imagine tall sunflowers reaching for the skies, but there is a great selection of dwarf sunflowers for pots so you can enjoy the blooms in smaller spaces. The flowers are often the classic yellow, but can also be shades of orange, red, and white.

Sow sunflower seeds around two inches deep in the soil and with 12 inches between each plant. Taller varieties may need stakes to keep them upright, as strong winds can destroy any display.

Zinnias

Zinnias are easy flowers to grow for bright and speedy summer blooms. Whether you are a beginner gardener or more experienced, zinnias are ideal plants to sow in spring as these fast-growing flowering annuals germinate quickly and can provide a long show of colorful blooms.

As zinnias can be temperamental to transplanting, planting zinnia seeds directly into the growing position takes away any form of risk. Pick a sunny planting spot with free-draining soil and sow the seeds directly in early June.

Keep the soil moist, and thin the seedlings to around 12 inches apart when they germinate. Don’t expect a long wait, though, as zinnia can germinate in under a week. In ideal conditions, the zinnias should start blooming within eight weeks from sowing.

Here are two tips for more flowers. If you pinch zinnias early in their growing season, you will encourage more stems to carry blooms, and regularly deadheading zinnias will mean a longer flowering season.

There are lots of zinnia varieties to choose from, but this packet of Dreamland Mixture Zinnia Seeds at True Leaf Market rewards you with a glorious mix of blooms.

FAQs

Is June too late to plant wildflower seeds?

June is not an ideal time to plant wildflower seeds. If you want to sow plants in a wildflower garden, the ideal times are in spring or fall. At these times of year, the weather is cooler, wetter, and more suitable for wildflowers.

While we’ve covered annual flowers to sow in June for quick pops of color in your beds and containers, there is also the scope to think a bit longer term.

This guide to perennial flowers to plant in June highlights a range of fantastic perennials that can be added to beds for years of glorious color. There are even some that can be sown from seed this month.