Maximum blooms for minimal effort – these 9 annuals will give even beginner and time-poor gardeners months of guaranteed summer color

Growing colorful annuals could not be easier with these fuss-free beauties. Filling your yard with beauty from early summer to fall, they are the perfect go-to plants for novice and time-poor gardeners alike.

Guaranteed to transform a pot, border or wider area with their showy blooms, they need very care once germinated. As long as conditions are right and they are watered during the growing season, these are amongst the simplest and best annual flowers you can grow.

As a keen gardener who’s been growing flowers from seed for years, I've had great success with many of these nine varieties. I’m not alone either, as our most trusted horticultural experts love them too. For the price of a packet of seeds, these are the annual flower varieties that will virtually look after themselves, filling your yard with months of glorious color.

Calendula

You can’t beat calendula or pot marigolds for easy to grow and instantly uplifting blooms. Delightfully simple in form and in shades from the softest apricot through to fiery orange, these blooms never fail to make an impact. The curved brown seeds are easily big enough to handle and they are pretty quick to germinate too.

Producing slightly sticky, bright green foliage, they are perfect for filling pots, edging paths and dotting between crops in the veg bed. In fact, they are highly effective companion plants, attracting beneficial insects such as hoverflies that will feed on damaging aphids, plus these pest repelling plants also emit a scent that ward off whitefly, flea beetle and other marauding pests.

Edible too, scatter the petals over salads, use in drinks, cakes and to flavour oils. Snip off any blooms that are past their peak to encourage other buds to develop. Take a look at this unusual multi-toned variety organic mix of calendula seeds from Walmart.

Poppy

Vibrant yet fleeting, silky petalled poppies - Papaver Somniferum - are one of the easiest annuals to grow. Scatter their dust-like seed outside where you want them to bloom, water lightly, sit back and wait for the delicate seedlings to emerge.

Don’t be fooled by their fragile appearance, these plants are tough – after all they appear in swathes in meadows without any help – all they need is regular watering during the growing stage and they will soon be dazzling with their blooms in shades of the palest lilac, violet to deepest burgundy.

Prolong the display with regular deadheading and either harvest the papery seedheads or leave in situ, to enjoy another colorful show the following year. Flowers can be delightfully ruffled, fringed, double or single.

You can find glorious 'Hungarian Blue' heirloom poppy seeds at Burpee.

Cosmos

The love for cosmos – those large, papery-petalled beauties – is clear to see. Adored by landscape designers, florists, cut flower farmers and gardeners alike, Cosmos bipinnatus epitomises the easy-going nature of summer and it’s extremely easy to grow from seed. Usually in shades of white, pink and red, they exude a cottage garden charm and attract pollinators such as bees, birds and butterflies.

'Cheerful, fool proof, and prolific! This low effort, high reward, annual wildflower is available in a wide variety of colors and petal shapes,’ says meadowscaping advocate Cullen Boudreaux. 'I’ve had equal success scattering over bare dirt and starting early, indoors, with soil blocks (once you fall in love with these wildflowers you won’t want to wait until your last frost to get started).'

Horticulturalist Katie Sunderlage is also a huge fan, 'I absolutely love growing Cosmos during the Summer months. They bloom all Summer long with little to no deadheading required and thrive in the heat of the Summer. Once established, Cosmos are drought tolerant and thrive in hot, humid conditions.'

Reaching up to heights of up to 24” (60cm), these plants may need staking in exposed or windy locations to prevent stems from snapping. A grow-through grid plant support such as this one from Walmart will do the job.

Cosmos stems make fantastic cut flowers lasting up to ten days in a vase. Cut them just before blooms are fully open and leave cut stems in cold water overnight before arranging.

You can find cosmos seeds mixes at great value from Amazon.

Zinnia

Sun loving zinnias are surprisingly straightforward to grow from seed. Their complex, candy-colored blooms are fascinating to behold and will add zest to any sunny patch or planter in the yard. Give them warm conditions in moist yet free draining soil and they will soon be dazzling you and other garden visitors.

‘Not only do they attract delightful pollinators, but zinnias are an easy and affordable way to fill your space with homegrown happiness all summer long,’ explains Cullen.

‘I recommend starting simple with a classic like cut and come again zinnias and later exploring the many gorgeous varieties available. Pinching will maximize blooms. Once your plants reach 8 to 12 inches tall, cut just above a set of leaves to remove the top 3 to 4 inches; this will force the plant to branch out and create more stems.’ Use your fingertips for this task or, alternatively, try a pair of narrow bladed garden snips such as these from Walmart.

Avoid overwatering and growing on heavy, clay soils, as these plants will struggle to thrive and bloom. Once seedlings are established zinnias are generally drought tolerant.

You can find gorgeous cut-and-come-again zinnia seeds at Burpee.

Nasturtium

These summer flowers are real ‘sow and leave’ plants, literally scatter the hard, spherical seeds in a sunny spot, cover them with a thin layer of soil and leave them to it. As long as some moisture finds the seed they will grow, producing their distinct rounded green leaves and jolly trumpet-shaped blooms. Many varieties of nasturtium or Tropaeolum majus have a trailing and tumbling habits, allowing them to scramble across paths, fences and walls. Dwarf varieties are becoming popular too, for their neater growth but equally prolific blooms.

Taking between 10-14 days to germinate and reaching heights of around 10” (25cm), these plants are perfect ground cover or pot fillers. With edible leaves and flowers – they have a punchy black pepper flavor – these cottage garden favorites can be used to pep up salads, tarts and grilled dishes.

Highly effective companion plants, nasturtiums are super handy for growing alongside veg crops. Luring leaf munching caterpillars away from brassicas and deterring aphids from attacking all types of beans, they can also attract hard working pollinators.

Popular seed collections – including Alaska, Jewel and Tom Thumb Mixes - feature yellow, orange and red flowers often with painterly markings but some more delicately shaded varieties can be found such as ‘Peach Melba’, ‘Moonlight’ and palest ‘Yeti’. You can discover lots of these varieties from the seed selection at Burpee.

Nigella

Another of my absolute favorite summer annuals to grow from seed is nigella or love-in-a-mist. Partly for the dreamy mix of blue and white shades (I’m personally less keen on the pink hues) and partly for the delicately intricate central stamens, no summer border in my garden is complete without a patch of these heavenly charmers.

I find it really hard to ignore the painterly charms of Nigella papillosa 'Delft Blue' and Nigella papillosa 'African Bride' – a mainly white bloom with deep purple-blue stamens, but there are plenty of tempting heirloom and new varieties to try, including the intriguing Nigella damascena, 'Albion Black Pod’ with its dramatically dark seedpods, available at Select Seeds.

Super easy going – and growing – simply scatter the glossy yet tiny black seeds directly into finely forked soil, ideally in full sun, and watch as the shoots emerge. Eventually reaching heights of around 20”(50cm) the feathery silver-green foliage intermingles to form a hazy cloud above which the papery blooms hover. A continual show of flowers dazzles from mid-summer through to the first frosts, with the petals giving way to sun-bleached, papery seedpods that look just as dramatic as the blooms themselves. Cut and dry them for seed or for popping into dried flower wreaths and posies.

Katie Sunderlage

Operations Manager at Holland Group, managing the customer service department and purchasing. Katie has been in the green industry since 2005 in the Greater Milwaukee area, earning her degree in Horticulture in 2008. She has been able to share her love for plants working in multiple garden centers, in sales positions and most recently in an online retail platform at Holland Group.

Cullen Boudreaux

Cullen currently serves as Director of Brand Expression for AmericanMeadows.com. She caught the gardening bug in 2011 when she began nurturing (and blogging) about her tiny garden in downtown Atlanta. In the years since she has become an advocate for the ways gardening improves our lives, our communities and our planet.

Coleus

‘I absolutely love the color coleus plants bring to a shady garden,’ says Katie. ‘Known for its colorful foliage, it comes in a wide variety of options from dwarf, large-leaf, trailing and upright so the possibilities are endless. There are some full sun varieties available, but coleus are generally used in shade gardens to help add color and vibrancy.’

These tiny seeds need warmth, light and humidity to germinate, so are best started indoors, pressing them gently into damp soil without covering them. Taking between two to three weeks to germinate, once they have their first proper pair of leaves, they can be moved to larger individual pots. ‘They tend to work best in a patio container or if a trailing variety, in a hanging basket,’ explains Katie.

Very susceptible to cold temperatures, coleus can easily become damaged if temperatures drop below 50 degrees. These plants can produce flowers spikes, but they are not as attractive as the multi-colored leaves, so are best snipped off to divert the plants energy into healthy, vibrant foliage.

Cornflower

Another of my absolute summer flowering favorites and perhaps the easiest annual to grow, cornflowers or Centaurea Cynus are essential in any flower border or grassy patch. They come in endless shades of blue, white, red, purple and pink – a variety for every planting palette and taste. From single starry flowerheads that look like mini explosions on a stem to the mini pompom-like double varieties including ‘Blue Ball’ and ‘Tall Double Red Ball’, these blooms really pack a punch of color.

Unfussy and resilient, these elongated seeds prefer poor soil in a sunny spot. Flowering just 10 -12 weeks after sowing, grow them outside in situ in late spring, early summer. As some cornflower varieties grow up to 39 inches (100cm), staking may be necessary to prevent the slightly brittle stems from snapping. Growing them through a wire or metal grid or net stretched taut between canes is a quick and easy solution. Once flowering, deadhead regularly and cut for indoor displays.

You can buy cornflower seeds at Amazon.

Sunflower

It’s hard to stop sunflower seeds from germinating, as you may notice when checking out the ground below any bird feeder. Take advantage of their resilience and grow some of these cheery summer blooms for your yard. Not only will they reward you with glorious flowers, but birds, pollinators and small mammals will adore them for their nutritious seedheads come fall.

‘Sunflowers grow quickly during warm weather to their mature size, which ranges from 1 foot to 15 feet tall,’ says Cullen. ‘Depending on the variety, you'll have one head per sunflower stalk or multiple heads. Multiple-headed varieties tend to be shorter and more manageable in the garden, while large headed varieties are great for producing lots of sunflower seeds.’

As the name suggests, these annuals love the sun and thrive best if planted where they are to flower. Although they prefer well drained soil, they will tolerate some sand and clay soils.

‘Keep young seedlings well-watered to prevent wilting and stunting. Add 2 gallons of water weekly - unless you are experiencing regular rainfall in spring and early summer,’ suggests Cullen. ‘Once the taproot develops, sunflowers are able to withstand drier conditions.’ A dose of diluted liquid fertilizer every couple of weeks during the growing period will aid strong, tall stems and plenty of blooms.

For spectacular, head-turning blooms try the dark centred Crimson Velvet Sunflower Seeds available at American Meadow or the petite flowering Rouge Royale Sunflower Seeds available at American Meadows

FAQs

What are the easiest annuals to fill a border?

If you're spoilt for choice and can't decide which flowering annuals to grow or simply want to fill a bare spot with floral color, you can't beat a ready-made wildflower or meadow mix of annuals.

‘For gardeners with experience growing vegetables or perennials, but not annual flowers, I highly recommend trying an all-annual wildflower seed mix,’ advises Cullen. ‘A seed mix allows gardeners to experience dozens of varieties, in a single space, with just one planting. This provides knowledge about bloom time, height, scent and what performance best in your space’s unique growing conditions.’

Super easy to sow, just dig a patch of soil over, breaking up any hard clumps, level and scatter the seed. Rake lightly and keep watered until the young plants are established.

Looking for more easy ways to boost your yard this summer? Take a look at these summer container planting ideas and the best cut-and-come-again flowers for continuous color.