Blue is beautiful! It's also not quite as rare in the garden as some people might think, especially when it comes to shrubs. You'll find fabulous flowers, foliage, and even fruit in blue hues that add a touch of cool and refreshing color to your garden or landscape. Blue goes with just about any exterior color, including red and orange brick, and plays nicely with other plants as well. When in doubt about how to accentuate your landscape, just go blue!
Pugster Blue® butterfly bush - Buddleia
One of the trickiest parts of blue flowers is that the camera rarely sees them the same way the human eye does. That's why you have to see a Pugster Blue butterfly bush yourself to appreciate its deep, true blue blooms, not to mention their impressive size and delightful honey-like fragrance. Like the rest of the Pugster series, Pugster Blue is a dwarf plant with full sized flowers. Its thick, tough stems give it better cold tolerance than other butterfly bushes, so it's the perfect choice for blue lovers in zones 5 and 6. 2' tall and wide. Full sun.
Beyond Midnight® bluebeard - Caryopteris x clandonensis
What makes blue flowers even better? Handsome foliage to perfectly complement them. That's what makes Beyond Midnight Caryopteris so special. Very dark green foliage accentuates the deep blue flower spikes that attract tons of pollinators. This plant blooms in late summer and fall, bringing welcome color when other things are winding down. Beyond Midnight should be planted in hot, sunny, well-drained spots and pruned back hard in spring. 2-2.5' tall and wide. Full sun.
Azurri Blue Satin® rose of Sharon - Hibiscus syriacus
Not only is Azurri Blue Satin the bluest of all blue roses of Sharon, it's also seedless – which means that this innovative variety won't cause seedlings to sprout up all over your yard. Its single flowers are deep cobalt blue in bud and open to reveal an entrancing violet eye. Rose of Sharon is naturally a pretty low maintenance plant, but seedless varieties like Azurri Blue Satin make it even easier to care for – which leaves you more time to enjoy it. Just be sure to plant it where you and your family can enjoy it on those hot summer days, whether from a shady porch seat or the comfort of air conditioning. 8-12' tall and wide. Full sun.
Blue Chiffon® rose of Sharon - Hibiscus syriacus
One look at this beautiful rose of Sharon and it's easy to see why it has gained international acclaim: its graceful branches are covered in powderpuff-like double blue blooms all summer. Those unique double blooms also have a benefit beyond beauty: this rose of Sharon sets little to no seed, so won't become a nuisance. Though it is quite a large plant, you can also find Blue Chiffon rose of Sharon grown as a space-saving tree form. Plant Blue Chiffon as a glorious flowering hedge, or a showy specimen. 8-12' tall and wide. Full sun.
You knew a hydrangea would be on this list, right? While most bigleaf hydrangeas are capable of turning some shade of blue, our best blue is Let's Dance Rhythmic Blue hydrangea. If conditions are right – that is, the soil is acidic and contains a good amount of aluminum, a naturally occurring soil mineral – its rounded mophead flowers will be that heavenly blue that so many gardeners covet. And Let's Dance Rhythmic Blue hydrangea is reblooming, continuing to create flowers on new wood, so you get more color in the same space. 3-4' tall and wide. Full to part sun; part sun only in hot climates.
Never heard of a mountain hydrangea? These plants are native to the same areas of Japan as the closely related bigleaf hydrangea, but because they are native to the cold mountaintops instead of the mild seaside, their flowers have naturally developed better resistance to cold. This means if bigleaf hydrangeas don't bloom for you, mountain hydrangeas will! Tiny Tuff Stuff hydrangea is the best blue of the Tuff Stuff series, with delicate lace cap flowers that turn sky blue readily in the right conditions. Dwarf habit lets you fit this blue beauty just about anywhere. 1.5–2' tall and wide. Full to part sun; part sun only in hot climates.
Blue Diddley® chaste tree - Vitex agnus-castus
Tough and versatile are great qualities for any plant – especially when combined with super-showy blue flower spikes and unique, high-quality foliage. Blue Diddley chaste tree brings a dwarf habit to the mix, further increasing the ways this sun-loving shrub can be used. Blue Diddley is also hardier than you might think for a chaste tree: it will readily survive in zone 5b as long as it has well-drained soil. Grow as a rounded shrub or small tree. 3-6' tall and wide. Full sun.
Blues Festival® St. John's-wort - Hypericum kalmianum
The cool blue foliage of Blues Festival St. John's-wort doesn't just keep this shrub looking great spring through fall – it's also the perfect foil for the bright yellow sunburst-like flowers in summer. This native plant naturally grows as a neat, rounded mound, which gives it superlative versatility in the landscape. The smooth blue leaves have a waxy coating that lets this plant shine, literally and figuratively. 2-3' tall and wide. Full sun.
Double Play® Blue Kazoo® spirea - Spiraea media
This spirea is a problem solver with panache. Like other spirea, it's extremely durable, tolerates dry soils, sun or part shade, resists deer, and needs pretty much no maintenance – and it does it all beautifully. The new growth emerges purple, green, and red before maturing to an easy-going blue that lasts all season. Enormous white flowers in early summer give it a cool and refreshing impression in the landscape. 2-3' tall and wide. Full to part sun.
All That Glitters® and All That Glows® arrowwood viburnums - Viburnum dentatum var. deamii
Enjoy three seasons of beauty with this pair of native viburnums. Late spring brings dense flower clusters of pure white; extremely glossy foliage carries the plants through summer. As autumn comes around, beautiful deep blue berries crown the plant. These two viburnums were selected to complement one another, ensuring you get that crop of fruit every year. Plant as a hedge, or in a foundation planting, or anywhere you need a large, handsome shrub – both you and the birds will love these viburnums. 4-6' tall and wide. Full to part sun.
All articles are copyrighted and remain the property of the author.
By Justin Hancock, Monrovia Horticultural Craftsman
Photographs courtesy of Monrovia
Labor Day may represent summer’s unofficial close but now is a perfect opportunity to add late-summer perennials that will continue to beautify your landcare until fall arrives. click here for an article that identifies 9 perennials for late summer.
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