Top 10 Beautiful Blue Flowers for Your Garden

01. African Blue Lily

Agapanthus africanus “Blue Globe”

Flowering time: August-September

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A South African native that provides spectacular color in late summer

It is odd in gardening how one man’s meat is another man’s poison: things that some people consider weeds are rare and lovely garden plants to others. Arum lilies (Zantedeschia aethiopica) are hunted down in New Zealand, and in South Africa agapanthus grows on roadside verges in the same way that thistles do on the central reservations of European motorways. Except the agapanthus is prettier. It seems weird that the agapanthus we much admire is treated with the same disdain there as we hold for dandelions.

Agapanthus africanus “Blue Globe” is undoubtedly spectacular, with great bunches of pure blue flowers held like lamplighter’s torches on long, elegant stems. The plants look particularly effective in large terracotta pots, especially as they flower much better if kept slightly pot-bound and constricted.

These plants hate waterlogged or heavy soil but still need plenty of moisture, and will suffer if allowed to dry out completely. Propagate by dividing well-established clumps in mid-spring.

02. Aster

Aster “Little Carlow”

Flowering time: August-October

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A charming and elegant daisy for late summer and early autumn

Asters (or Michaelmas daisies) are often perceived as quite granny-ish plants. They flower vigorously but can be a bit leprous being almost always stricken with the white bloom of mildew.

“Little Carlow” is slightly different: for a start it is not one of the novi-belgii cultivars, but a hybrid of the much tougher A. cordifolius. The flower is much more soignée: instead of closely bunched and, frankly, rather lumpy blooms we have clouds of daisies the color of thrice-washed denim. The centers are a refreshing yellow, and the leaves are small and heart-shaped.

Best in moderately fertile, moist soil in semi-shade, but it will tolerate full sun at a push. Divide plants in spring, replanting only the most vigorous shoots. Seed can be sown spring or autumn.

03. Delphinium

Delphinium elatum “Joan Edwards”

Flowering time: spring-summer

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A perennially popular plant, known by all and loved by most

“There once was a Dormouse who lived in a bed, Of delphiniums (blue) and geraniums (red)”. All was well until some interfering doctor came along and changed all his flowers to yellow and white chrysanthemums, after which the dormouse seldom opens his eyes again. It is all in the A.A. Milne poem if you want to know more, but my instincts say that, given the choice, most people would opt for delphiniums over yellow chrysanthemums.

Delphinium elatum “Joan Edwards” is one of the everlasting classics of the herbaceous border. Soaring spires of gorgeous blue add enormous solidity and spectacle to mid-summer borders. This is a plant that was born to dance with old-fashioned roses, creamy lupins and red geraniums.

Best in full sun out of strong winds, it needs staking in about March before it starts growing. Propagate from basal cuttings (the thickness of a pencil) taken in early spring. Watch out for slugs.

04. Liverwort

Hepatica nobilis

Flowering time: February-May

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A winter flower for the woodland

It sometimes seems that, every so often, when taxonomists are getting bored of sitting there naming plants all day, they liven things up by dumping an appalling name on some poor, unfortunate plant. Thus this spectacular (though tiny) plant is lumped with the common name of liverwort because it was used as a medicinal herb and the three-lobed leaves resemble the human liver.

The flowers are clear purple-blue and, if you are very lucky, are even better when pushing through the lightest covering of snow. The magenta- splashed leaves appear a few days after the flowers. Hepaticas are found all over the world from Japan to Scandinavia via the Carpathian Mountains.

Best in a shady garden. Sow seed in summer or you can divide plants, but they will be slow to recover. There is a danger of slug damage when plants are young.

05. Beardless Iris

Iris “Broadleigh Penny”

Flowering time: May-June

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An elegant flower for lightly-shaded places

This is a hybrid taken from the irises of the Pacific Coast and is without the characteristic fluffy goatee beards that the more popular German irises have. They are, however, no less lovely, and in fact they can be more useful in mixed plantings as they will tolerate a bit of overshadowing by other plants, so they are ideal for areas of light shade under shrubs.

Where Iris germanica has large flowers with ostentatious hills, this hybrid is more like a sleek Californian surfer with slim leaves and cinch- waisted petals. The flowers are occasionally mistaken for orchids because of the subtle colors and prominent markings on each petal.

Seeds should be chilled after sowing by placing them, and their container, in a fridge (not a freezer) for three weeks. Irises prefer neutral to acid soil. Divide in autumn.

06. Himalayan Blue Poppy

Meconopsis “Willie Duncan”

Flowering time: April

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A serene and breathtakingly gorgeous perennial poppy

This is possibly one of the bluest flowers in the world. Meconopsis “Willie Duncan” is the blue of Everest skies, of glacial torrents over glass smooth pebbles and of the sparkling eyes of Nordic princesses. To see them in a drift under the young lime-colored leaves of immature trees is a near-­spiritual experience.

The seed of this poppy variety was first brought to the UK in 1924 by the famous plant hunter Frank Kingdon Ward, to immediate sensation. A poppy this color was a revelation and, by 1927, there were huge public displays in London and Edinburgh.

The Himalayan blue poppy is a plant that needs acid soil and it grows particularly well in the cooler, rainier parts of the country (particularly Scotland and the south west).

Sow seed thinly in pots as soon as it is ripe (late spring) in loamless seed compost. Mulch adult plants generously with leaf mold. Grows to about 1.2 m (4 ft) high.

07. Love-in-a-mist

Nigella hispanica “Midnight”

Flowering time: June-August

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A heavenly annual that is ridiculously easy to grow

If there’s a top ten of the easiest plants to grow, then this is in the top five. Instructions for use are as follows: sprinkle a packet of seed around in spring and then go off and have a drink. That’s all. Within a short space of time you will be rewarded by a sea of lazy-eyed, dusky blue flowers surrounded by a fine froth of feathery foliage.

The flowers of nigella are the love, the leaves are the mist and the combination is captivating. It doesn’t stop there, though: as the blooms fade they morph into puffy, spider-legged seedpods. As the autumn approaches, these pods split and shiny black seeds are spread around the garden.

It is a supremely romantic plant where both flowers and seedpods are perfect for picking and flower arranging. This plant also comes in paler blue, white and degrees of pink. Totally trouble-free.

08. Sand Phlox

Phlox bifida “Ralph Haywood”

Flowering time: late April

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A low-growing plant with lots of scented flowers; good in rockeries

There are a lot of different phloxes around and all of them are native to North America – except one lonely Siberian. They range from tall ones in many colors, which are best for the late summer border, to small annuals that are suitable for bedding out.

Phlox bifida “Ralph Haywood” is a scampering little perennial that forms neat evergreen mounds which grow to about 20 cm (8 in) high. The official botanical description of the flowers is that they are “salverform and borne in abundant cymes”. Roughly translated this means that there are lots of flat- topped, pleasantly fragrant, star-shaped flowers that look a little like paper doilies – albeit rather superior ones. They are a rather comforting deep lavender blue, like the bath salts sold at village fetes.

Propagate from softwood cuttings taken from non-flowering stems in spring. The plants are happy in poor, well-drained soil and will thrive in either full sun or slightly dappled shade.

09. Sage

Salvia patens “Dot’s Delight”

Flowering time: July-October

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Palest blue tender plant for pots or borders

Behold one of the finest members of the large sage family: a genus with about nine hundred assorted aunts, uncles and cousins from all over the world. This is a tender Mexican perennial that is perfect for filling post-bulb gaps and adding a little class to late-summer borders (when things tend to get a little straggly and rowdy).

The flower is shaped like the wide-open beak of an exotic bird swooping down to snatch an unsuspecting mouse from the bosom of its family. Except that, in spite of the cavernous maw, this plant is far too delicate to be carnivorous; if it was a bird of prey it would probably only eat windfall apples and fairy cakes.

Sow seed in mid-spring or take basal cuttings in late summer. Protect young seedlings from the rapacious ways of slugs and snails. Needs plenty of sunshine and good drainage.

10. Horned Violet

Viola “Columbine”

Flowering time: May-August

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Short and delicately colored violet that flowers all summer

One of the popular activities amongst pre-school children is marbling paper. This involves floating colorful dollops of paint on water and then dipping paper into the mixture. These are then brought back home so that proud parents can stick them on the fridge. This little violet looks as if it has been put through this process.

A pale, cream-colored flower, Viola “Columbine” appears to have been dragged through a sky blue puddle that has resulted in remarkably pretty veining across its tiny petals. It is only about 20 cm (8 in) high and makes a really excellent, long- flowering, front-of-border plant. The leaves are heart-shaped and the flowers make an exciting addition to a salad – more for the color than the taste.

Cut back after the first flush of flowers and it will happily repeat all summer. Sow seed when ripe or save until spring. Save seed in paper envelopes in a dry place.

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