15 Summer Flowers to Plant in 2021

As regular readers, and students on my course, Self-Sufficient Veg Gardening, will know, I’m a keen vegetable grower. In fact you might say that’s pretty much all I grow – well, that and lots of fruit and herbs, of course.

But I have a confession to make. Don’t tell anyone – but I grow flowers, too. Lots, actually.

There are really good reasons for including flowers on the veg plot. For one thing, they look pretty: veg can be a little plain green sometimes, so a splash of gold, blue or scarlet really brightens the place up. More importantly, though, they’re magnets for bees, butterflies and other pollinating insects – and while they’re buzzing around the flowers, they’ll often visit your beans, peas, courgettes and cucumbers too, boosting your harvest.

Right now is peak season for summer flowers – but don’t worry if you’ve left them out of your pre-season planning. It’s a little late to sow many flowers now, as most annuals are flowers to plant in spring for summer blooms. But there are some which you can sow now and still expect flowers by the end of the year.

The best flowers to plant in summer are those which germinate quickly, reach flowering size in double-fast time and go on flowering till the first frosts cut them down, so you can keep enjoying them well into autumn and beyond.

And of course you can also fill your garden with colour by cheating – annual flowers are also available as ready-grown plug plants for an instant hit of colour (suttons.co.uk do a great range, all raised in peat-free compost, too).

Here are my top 15 best summer flowers to plant right now: get these in the ground tucked around your late-summer veg and your patch can still look a million dollars before the season is out.

Nasturtiums Cheating a little, this one – as nasturtiums are really salad ingredients. All parts are edible, including the dayglo-bright flowers: sow from seed now and they’ll bloom before winter.

Cosmos A bit late to sow direct, but readily available as plug plants, cosmos are graceful daisy-like flowers on wiry stems – and the more you dead-head them the more flowers they’ll produce.

Pot marigolds I have pot marigolds self-seeding round the garden all year and even from July seeds they produce their cheerfully sunny yellow daisies well before summer is out.

Zinnias These Mexican sun-lovers actually do best from a late sowing as they need the ground really warm. Truly head-turning primadonnas, they come in a range of dazzling colours.

Sunflowers Yes, really: sunflowers grow like topsy and this time of year you can sow direct. Choose a dwarf variety like Little Dorrit and you’ll fill your garden with sunshine by September.

Borage Another cheat, as borage is a lovely fragrant herb and a great companion for tomatoes and strawberries as well as having the prettiest blue flowers. Sow direct for flowers by autumn.

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Planting Design with Perennials

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Gazania Jewel like flowers in shades of bronze, yellow and tangerine just keep coming till the first frosts. You can buy them now as inexpensive plug plants, ready to flower.

Clarkia Super-speedy and easy-going, clarkia just need scattering on warm, damp ground to spring to life: the deeply-cut pinky-purple flowers keep coming till frost cuts them down.

Poached egg plant (Limnanthes douglasii) Low growing and ground-covering annual that’s a doddle to sow and very fast-growing; it also self-seeds readily so you’ll never need to sow it again.

Alyssum A good go-to edging annual that froths with pure white, snowy flowers all summer; sow now and you should have flowers by autumn.

Love-in-a-mist (Nigella damascena) Beautiful starry blue flowers followed by architectural seedheads that last for ages; they’re really fast to germinate and flower well into autumn.

Dahlias It’s too late to sow dahlias from seed, but you can buy annual dahlias as plug plants or splash out on a larger potted plant: deadhead regularly and these glamourpusses flower till winter.

Night phlox (Zaluzianskya capensis) Super-fast to germinate and reach flowering size, this lovely delicate annual is heavily scented but only in the evenings as it’s pollinated by moths.

Swan river daisy Sow direct into warm, damp soil or buy in plug plants for a froth of pink, purple and white that’ll last the rest of the summer.

California poppy One of those annuals that grows almost whatever you do to it, with ferny foliage and clear orange, red or yellow flowers; self-seeds readily so you’ll have it popping up for years.

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For more advice on planting combinations check out Dr. Noel Kingsbury's online course Planting Design with Perennials and get his advice on what you should be planting this year. You can also join me in my Self-Sufficient Veg Gardening class and learn how to make the most of your garden so you can enjoy the superb flavours and freshness of home grown fruit and vegetables.