12 True Blue Perennials For Your Garden

Spruce up your landscaping with some blue flowers. These stunning blue perennials are just what you need to break up the greens and pinks, or to combine with your white and red flowers for a patriotic theme.  

Here’s a fun fact … naturally blue flowers don’t exist. That’s because plants cannot produce a true blue pigment. The perennials on this list – or any other list you find – are not technically blue but are blue-toned purple or lavender.

Don’t let this fact give you the blues. Take a look at these 12 flowering perennials that are close to being blue to give you the color scheme you want without looking unnatural.

1. Delphiniums

Delphiniums are flowering perennial plants that can grow up to six feet tall. It is also commonly called larkspurs because of the spiky appearance of the flowers.

Blue is the most common color of delphiniums, but you can also find them in other colors.

The flowers of the delphinium plants have a unique structure, with five petal-like sepals that are fused together to form a tube. The center of the flower has a prominent cluster of stamens that give the flowers a distinctive pointed appearance.

Their unique color and shape provide a dramatic contrast to flower beds.

Delphiniums can be somewhat finicky to grow. They need frequent watering, but are prone to stem rot if they get too much water. With ideal growing conditions and proper care, however, delphiniums can give your landscape a pop of blue.

2. Periwinkle

Periwinkle, also known as vinca, is a low-growing evergreen groundcover plant that produces a profusion of small, bluish, star-shaped flowers. The flowers bloom in spring and early summer and often continue blooming sporadically throughout the growing season.

The flowers of the periwinkle are usually about one inch in diameter and have five petals. The center of the flower forms a nectar-filled tube that attracts butterflies and bees. As the name suggests, the blooms are a light, dusty bluish-lavender color.

Periwinkle is often used as groundcover in gardens and landscaping and in natural areas. It is a low-maintenance perennial that grows well in shade or partial shade. It has a habit of spreading rapidly, though, so you may have to cut it back from time to time to keep it from taking over.

3. Columbine

Flowering columbine blooms with dainty, bell-shaped flowers that can be brilliantly blue in color. The flowers are easy to identify because of their five petals encircling a center cluster and the longer double petals that spread from the base of the flower.

The Colorado blue variety of columbine is the state flower of Colorado and is a sky-blue color. It grows in the woods and open meadows of the Rocky Mountains, although it has become more popular in recent decades as a garden perennial.

Gardeners are drawn to the unique flowers and the stunning blue color… and bees, butterflies, and hummingbirds are drawn to the columbine for its sweet nectar.

4. Morning Glories

Morning glories are so named because they typically bloom in the morning and close up their petals in the afternoon and evening.

The climbing vine with the large, blue, trumpet-shaped flowers is grown as a perennial in warmer locations and as an annual in cooler climates.

The petals of the morning glory flower are fused together to form a trumpet-like structure. The flowers can be two to three inches in diameter. The leaves are heart-shaped and can be between two and four inches long.

Morning glories are climbers. The plant grows rapidly and needs a structure, like a fence, arbor, or trellis, to cling to. They make a charming addition to a cottage or wildflower garden.

Like some of the other flowers on our list, the color of morning glory flowers can change in response to the pH levels of the soil.

5. Lupine

In some parts of the United States, lupines are known as bluebonnets. This member of the legume family produces tall spikes of showy, pea-like flowers in vibrant, electric blue.

The flowers, each only about three-quarters of an inch long, are packed tightly in clusters along stems that can be up to one foot tall.

Lupines spread easily and grow in large patches. When you happen upon an area where the bluebonnets are all in bloom, it looks like a giant blue blanket has been spread on the ground. Lupines, sadly, have a fairly short blooming season.

In flower beds or as landscaping groundcover, gardeners will have to carefully manage their lupine to keep it from aggressively spreading.

6. Bellflower

Bellflowers are so named because the five fused petals form a bell shape. The flowers are arranged in clusters along the stem.

The plant’s blooming season is quite long – from spring until fall, depending on the variety and the growing conditions.

Some varieties of bellflowers stay low to the ground and are ideal for ground cover. They are spread by runners. Other varieties can grow to six feet tall and form upright stalks.

The blue blooms of the bellflower are perky and upright, making them a lively perennial to include in your landscape design.

7. Wisteria

A climbing vine with a blue cascade of flowers, wisteria is a perennial that oozes romance. In fact, in Korea, wisteria flowers symbolize love that transcends death.

The beautiful dripping flowers, especially the blue ones, conjure up images of whimsical Victorian love stories.

Wisteria plants can climb up to thirty feet. Although they prefer a solid structure, like a garden arch, they can create their own support if none is available to them. Their central stem will thicken into a small tree.

Each individual flower of the wisteria plant is tiny, with a banner petal, two wing petals, and two fused petals all forming a curve. The flowers grow in clusters in lengths of up to one foot that dangle from the vines to create a curtain-like effect.

Wisteria smells as great as it looks. The flowers give off a sweet, floral fragrance that adds to their charm.

8. Forget-Me-Not

The tiny, blue forget-me-not is the state flower of Alaska. Native to alpine climates, forget-me-nots are finding their way into home landscaping because gardeners are charmed by this dainty yet hearty flower.

The petit blue flowers are less than one inch in diameter. They have five petals surrounding a bright yellow center. The plant grows in clumps so you will see a mound of small blue blooms.

Ideal as a ground cover or as an ornamental border plant, forget-me-nots may be small in size, but they pack a lot of sentimental value. Many cultures revere the forget-me-not as a symbol of mourning and grieving.

9. Hydrangeas

Hydrangeas are prized for their large, beautiful, pom-pom flower clusters. The flowers range in color from blue and purple to pink and white. But don’t go into your local garden center and ask to buy a blue hydrangea.

Many gardeners are excited to include blue hydrangeas in their yards. The blue color adds an unexpected twist and reflects the clear blue of the sky.

Hydrangeas are one of the perennial flowers on our list that are impacted by soil acidity. If you want bluer flowers, you’ll need acidic soil. If your soil is more alkaline, the hydrangea will produce pink flowers.

Don’t worry if your soil is naturally more alkaline than acidic. You can alter the pH levels of the soil surrounding your hydrangea plants by adding organic material, like orange peels and eggshells, to encourage your hydrangea to give you the blue flowers you desire.

10. Plumbago

A low-maintenance shrub, plumbago’s icy blue flowers make it stand out from other garden selections. This plant is also called sky flower and leadwort.

Both the leadwort and plumbago names originated with the ancient Roman naturalist, Pliny the Elder, who noted that the bluish color of the plant resembled lead.

Plumbago has small, star-shaped flowers that grow in clusters on long stems. Individually, the flowers are just under an inch in diameter, but when grouped together, they make a splash.

To add to their appeal, the blooms are quite fragrant and pleasing to smell.

The plant typically grows as a vine and will climb and trail. In fact, Plumbago can grow up to ten feet tall. Regular pruning, however, will keep the plants smaller, tidier, and more manageable.

11. Cornflower

A member of the aster family, which also includes daisies and sunflowers, cornflowers are also known as bachelor’s buttons. According to folklore, young men stuck a cornflower in the buttonhole of their jackets to signify that they were available to court.

The crisp blue color is the plant’s natural flower color. Botanists have hybridized the cornflower to come in a wider range of colors, but blue is its original hue.

Cornflowers have a central disk of tubular florets surrounded by a ring of bright, colorful petals. The petals are often fringed or serrated, giving the flowers a delicate texture. Each flower is typically less than two inches across.

The plants themselves are typically tall and slender, with pointed green leaves. Cornflowers last a long time after they are cut so they are often used in bouquets, corsages, and boutonnieres, and in other floral arrangements.

12. Blue Phlox

A shade-loving wildflower, blue phlox, or sweet William as it is sometimes called, blooms in the late spring or early summer, and the flowers last for more than a month. Some varieties, particularly the Wild Blue Phlox, are a bright, jolly blue color.

The perennial plant can reach heights of up to four feet tall. The phlox sends up tall, straight stems that are topped with a grouping of small flowers. Together, they give the appearance of a much larger bloom.

There are several reasons why gardeners would want to add blue phlox to their flower beds. The tall plant gives the garden height, visual appeal, and the look of a mature garden.

The unique blue flowers offer a dramatic contrast to other flowers in the garden and the blooms attract pollinators, like hummingbirds, bees, and butterflies. 

Summary

While the blue perennial flowers on this list might not be as blue as Elvis’s suede shoes, many of them are closer to blue than to purple on the color spectrum. Blue perennials are different and unexpected. They add a quirky, romantic, and elegant vibe to your garden space.