Blue is a very relaxing color that makes you think of tropical seas and clear skies, and trees with blue flowers are a prize to have in your garden. Small touches of purple in blue surrounded by the green foliage gives you a very unique and eye-catching look that draws people to it. They can blend surprisingly well with shrubs that offer purple or red foliage, or they also go well with flowering trees in shades of orange and yellow.
But, there are actually very few trees with blue flowers available. Jacaranda is one of the most prominent examples, and it’ll allow you to introduce shades of cobalt, ultramarine, azure, or cyan into your garden high up in the trees. You can also train shrubs to take on a small tree form and extend your plant’s range to fill in any gaps. Also, you’ll find trees with blue flowers to suit a range of growing zones.
However, not every small shrub will do well if you decide to turn it into a small tree, so we picked out a range of trees with blue flowers. We’ll go over how to keep them healthy and make them thrive below.
11 Beautiful Trees with Blue Flowers
Even though this isn’t a long list, each tree has stunning blue flowers on it. You can train them to grow in a variety of shapes too.
1. Blue Butterfly Bush (Buddleja davidii)
The first tree with blue flowers on the list is a taller shrub that you can train to grow to look like a tree, and it comes from the Scrophulariaceae family. It’s native to China, but it has been introduced to many other areas around the globe, including in the United States and Europe. Another name for this option is blue cat’s whiskers. The flowers are a striking color that blooms throughout the summer months. This butterfly bush is very easy to grow, and it’s decently resistant to diseases. Cuttings, seeds, or grafting all allow you to propagate this butterfly bush.
Left alone, this plant can easily reach up to 10 feet high at full maturity. It prefers to be in a well-drained soil under full sun, and it’ll adapt to a large range of soil types, including clay-based soil. This is a very popular plant to landscape with, and it’s commonly seen dotted throughout butterfly gardens or used as a hedge plant. It likes to be pruned, and you can easily prune it to get your desired shape. When you leave it and don’t prune it, it can spread over 10 feet wide. There are many medicinal properties attached to this tree with blue flowers, and you can use the stems, leaves, and flowers to make a tea. These teas come with a host of health benefits, including helping digestive issues and relieving anxiety.
The Blue Butterfly Bush is related to other blue flowers, like lavender or mint. However, the stunning blue flowers it produces makes it more tree-like. This is also an evergreen that will produce flowers from early spring until late fall. It produces larger, significant branches with thick foliage, and this makes it a very desired plant in many parts of the world. They grow best in subtropical and tropical climates, and they do very well planted in greenhouses. You’ll want to give them plenty of water and keep the pH levels in the soil between 6.0 and 7.0. For the best results, plant them in zones four to eight.
2. Blue Chinese Wisteria (Wisteria Sinensis)
Did you know that you can train this tree with blue flowers to get a very oriental look with stunning dropping blooms and arching branches? It works very well when you plant it in a Japanese-style garden or in more informal designs. This is a climbing shrub that hardens and thickens the stems so much that you can easily rest on the trunk if you keep it smaller. It has gorgeous blooms with a very strong, floral fragrance to it. Once the blooms die back, you can still get a show with the pinnate, green leaves that form a very finely textured canopy that will stick around until the end of the fall months.
Wisteria is adored by pollinators and butterflies, and it will bring elegance and color to any garden. To make sure that it takes on a tree form as it grows, you’ll want to guide two or three stems to twine around one another until they harden into wood. Get a strong support system in place for the early years. Once the plant matures, you can remove the support and prune your branches to form an umbrella shape.
For this tree with blue flowers to grow well, you’ll want to plant it in zones five to nine. It likes full sun, but it can also grow well in partial shade as long as it gets morning sunlight. It will get 10 to 30 feet tall, depending on how you train it, and it’ll spread between 10 and 15 feet. But, if you want to get a tree form, it’ll top out at 8 feet wide and 10 feet tall with pruning. The soil should be medium fertile and well-drained clay, loam, sand, or chalk-based. The pH levels should go from mildly alkaline to mildly acidic, and it’s very tolerant to drought.
3. Blue Hong Kong Orchid Tree (Bauhinia Grandidieri ‘Blue Hong Kong’)
Orchid trees are called so because the blooms are so showy and exotic that they look like orchids. This is a rare tree with blue flowers that offers an unusual color for the species as you get pale lilac blue. These colors may fade as they mature later in the season, but they will turn the branches into show-stoppers when they bloom.
The flowers reach an impressive six inches wide, and they have five distinct arching petals that look like the wings of a butterfly, and they emit a very pleasant but strong scent. It will bloom for months at a time before giving way to pods, since they’re relatives of peas, and the pods are edible.
The crown on this tree with blue flowers has an open and rounded habit, and the green leaves offer an exotic look as they have large lobes. This is a natural tree, so you won’t have to train or breed it to get this shape. However, you should note that this plant isn’t cold-hardy, but it’s nice to have if you live in warmer zones.
To get this tree to thrive, plant it in zones 9 to 11, and make sure that you put it in a space that gets partial shade or full sun. It will bloom from fall until late spring, and it’ll top out between 12 and 20 feet tall and 20 to 25 feet wide. So, you have to give it room to spread out when you plant it. The soil should be a very well-drained chalk, sand, or loam base with a pH range from alkaline to acidic. It tolerates drought well.
4. Blue Satin Rose Of Sharon (Hibiscus Syriacus ‘Blue Satin’)
Like any Rose of Sharon plant, this is actually a shrub that is very easy to train to grow as a tree with blue flowers. You’ll get large, rounded violet-blue blooms that have very dark purple veins running through them and a dark purple center all summer long. Each blossom is roughly four inches wide, and the stamens and tubes that project from the middle of the plant are creamy white to lighten up the color palette.
The deep green, large lobed leaves this plant produces are very dense, and they go very well with the display of flowers. However, since this is a cultivar, you won’t be able to propagate it by seed. To make sure that your plant turns into a small tree with blue flowers, pick one healthy and upright stem and prune away all of the others. Stake this stem until it gets two inches thick and hardens, and prune away all of the lower lateral branches for the first few years. Eventually, you’ll get a rounded crown packed with flowers.
The Blue Satin Rose of Sharon grows best in zones five to nine, and you want to give it full sun or part shade. If you do, it’ll start producing flowers from the middle of summer until late fall. It’ll get between six and nine feet tall at full maturity, and it’ll spread out between three and six feet. The soil should be medium fertile and evenly humid but drain well. You want a loam or sand-based soil with a pH range of mildly alkaline to mildly acidic. Once it’s established, it’s tolerant of drought and heavy clay soils.
5. Empress Tree (Paulownia Tomentosa)
You may hear this tree with blue flowers referred to as Paulownia or the princess tree, and it’s the fastest growing tree on earth. The flowers can be a lilac blue color, but most varieties come in lilac pink. You will need to carefully pick out your specimen if you want the blue flowers. Once you get past this hurdle, you’ll get this larger tree with funnel-shaped, giant blooms. You can even grow it from seed.
In a few short years, this tree’s crown will fill with foxglove-like flowers, and it starts blooming in the early spring months. The dark to mid-green, large leaves will come next, and they will hide the pointed and green pods that follow the flowers. You mainly grow this tree with blue flowers for the timber, but it’s also an eye-catching specimen plant. It’s been the recipient of the Royal Horticultural Society’s Award of Garden Merit, and it’s a nice pick if you need to quickly fill space in your garden.
To be successful with this tree with blue flowers, plant it in zones five to eight. Make sure that it gets full sun and you’ll see it bloom all spring. It gets between 30 and 40 feet tall and wide at full maturity, and it needs a humus-rich, fertile soil that drains well and has a lot of loose loam or sand. The pH can be anything from mildly acidic to mildly alkaline, and it’s tolerant to drought conditions.
6. Green Ebony Tree (Jacaranda Mimosifolia)
When most people picture a tree with blue flowers, this is the one that comes to mind. It’s a very elegant looking option to add to your garden, and it originates in South America. You’ll get large clusters of funnel-shaped blue flowers during the later spring or early summer months, and each will get roughly eight inches long. They come so packed on the tree that the whole crown will turn a deep blue color when they bloom. The branches are also very elegant, and they feature an open growth habit. The foliage is very small, so the flowers can take center stage when they bloom.
When the leaves form on this tree, they are segmented and long, and they form a lot of leaflets like you’ll see with mimosa. These leaves will form a finely textured, light crown that provides a backdrop for the flowers. It was the winner of the Award of Garden Merit from the RHS, and it thrives when you plant it in warmer climates. You’ll find it growing in public parks and along the streets in Mediterranean cities, but it can also grow very well if you plant it in California or Florida in the right region.
This tree with blue flowers will grow very well in zones 10 and 11 under full sun. It’ll start to bloom late in the spring and into the early summer months, and it can get between 25 and 50 feet tall and 15 to 30 feet wide. You’ll want to plant it in moderately fertile soil that drains well but stays evenly humid with an alkaline or acidic pH level.
7. Ironwood (Memecylon Umbellatum)
Ironwood is a medium-sized tree with blue flowers that is native to India, Southeast Asia, and Sri Lanka. You may hear it called Blue Mist because it produces fluffy flower clusters. The flowers come generously throughout the glossy, leathery deep green, broad evergreen leaves. The flowers open straight on the younger branches, and they produce five petals and blue stamens that radiate out to give you a very delicate and fine texture.
You’d be hard-pressed to find a more stunning contrast between the foliage and the flowers. It’s mainly grown for medicinal purposes, and you can extract a yellow dye from the leaves to make it a very decorated plant. Also, you’ll also get very small, rounded, blue-tinged fruits. The biggest issue you’ll have is this tree with blue flowers is sourcing one because it’s not nearly as common as a garden specimen. However, you can grow them from seed or layering, and floral displays are making it more popular.
For this tree to thrive, you’ll play it in zones 11 to 12 as a general rule. It likes partial shade or full sun, and it’ll bloom from mid-spring to early in the summer months. It’ll top out at 20 to 33 feet tall and up to 15 feet wide, and it needs humus-rich and very fertile soil. It can tolerate poorer soils, but this can impact flower production. The pH levels should be neutral, and it can tolerate salt.
8. Lignum Vitae (Guaiacum sanctum)
This shrub is one that you can train to grow like a tree, and it’s part of the Zygophyllaceae family. It’s native to Mexico, the Caribbean, and Central America. You can also find this tree with blue flowers growing in Florida, South America, and Texas. The name translates into the wood of life, and it was originally used to create medicines that treated a host of diseases, including arthritis. It’s also a part of the Verbenaceae family.
This tree can easily reach heights up to 100 feet at full maturity, and it produces very dark green leaves with blue-tinted flowers. The wood is very dense and hefty, and it’s used to make cricket balls and pool cues. It may have moderate sun needs, but it prefers to be in full sun with a soil that drains very well. It’s actually tolerant of a large range of soil types, and this includes clay. You won’t find this tree used as a landscaping plant a lot because it’s hard to transplant and it’s very slow-growing.
However, the wood is very commonly used for carving projects. It has many medicinal properties attached to it too. You can use the leaves and bark to make a tea to treat colds and fevers, and the tree has a place in traditional medicine to treat joint pain and arthritis. The tree is endangered, so you may have a hard time finding one. If you do, plant it in zones 9B to 11, water it once a week, and keep the soil pH between 5.0 and 7.0.
Blue rhododendrons are a treat to find. This is a hardy bush that you may hear referred to as azaleas, and it’s part of the Ericaceae family. The name is Greek, and it means rose tree. This tree with blue flowers can easily reach between 6 and 10 feet tall at full maturity, and it has trumpet-shaped flowers with very broad leaves.
This plant is native to Asia, Europe, and North America, and it was first introduced to England by explorers from the Alps. If you prune this plant to be single-stemmed, you can get a tree-like growth habit. The biggest rhododendron tree is located in England, and it’s over 120 years old with measurements of 50 feet. This is a relatively easy to grow plant that is resistant to diseases. Cuttings, seeds, and grafting allows you to propagate this plant. They prefer well-drained but moist soil and full sun conditions to thrive. They’re also tolerant of a broad range of soils, including clay-based ones.
Rhododendrons are native to Asia, Europe, and North America, and you can find it happily growing in bogs, heaths, and woodlands. The blue rhododendron comes with several subspecies that vary in color from purple to pink, to white to blue. It blooms from late spring to early summer, and the flowers tend to grow in clusters and be extremely showy. You can use this bush in informal garden designs and hedges. There are also many medicinal properties attached to this plant, and the flowers, leaves, and stems are popularly used to make teas that work to help with digestive issues and help lower anxiety.
10. Texas Mountain Laurel (Sophora Secundiflora)
This is a very slow-growing evergreen shrub or a small tree with blue flowers that produces pendulous clusters of blooms that get packed tightly on the tree. Mountain Laurel looks a lot like Wisteria, and they also have a very sweet and strong scent that is very similar to bubblegum. They’re packed with pollen, and they attract a host of bees and butterflies. The foliage is very tough, dense, and leathery while being olive green and glossy. Each leaf forms a pinnate arrangement.
It will also produce pastel brown pods that will add to this plant’s decorative value. However, you should be aware that the seeds and flowers are narcotic and toxic. If you want it to form a tree shape, you’ll have to cut off the lower branches on this plant when it’s young. It’s also a good idea to shape it into a multi-trunked tree that works well in informal but lush gardens.
To get this tree with blue flowers to grow well, plant it in zones 7 to 10 under partial shade or full sun. It’ll bloom in the spring months, and it’ll get between 15 and 25 feet tall and 8 to 10 feet wide. The soil should be medium-fertile and drain well. It likes evenly humid sand or loam-based soil that has a pH range of neutral to alkaline. It’s also tolerant to rocky soils and drought conditions.
11. Victoria California Lilac (Ceanothus Thyrsiflorus ‘Victoria’)
The final tree with blue flowers on the list is a California lilac that offers blue flowers, and this particular cultivar offers the purest indigo shade you can find. The flowers are so thickly packed and profuse that they will cover the entire crown of the tree for two months in the spring and summer months.
The display this lilac plant puts on with the naturally arching branches give it a very elegant shape. The leaves are deeply veined, small, dark green, and shiny. Deer will leave this plant alone if you live in the country, but hummingbirds and butterflies will flock to it due to how many blooms it produces.
While this plant is naturally a shrub, you can train it to grow as a small tree by keeping one branch staked so it keeps it straight when your plant is young. Keep the lower part pruned of any shoots and only allow the upper branches to grow into arching forms to create the crown. IT’s great for coastal gardens, and it thrives when you plant it in zones 7 to 10. Give it full sun and it’ll grow between four and six feet tall with a 9 to 12 foot spread. It likes well-drained loam with medium fertility, and the pH levels can range from neutral to mild alkaline. It’s salt, rocky soil, and drought tolerant too.
Now you have it. We’ve outlined 11 great choices when it comes to trees with blue flowers that will create a stunning statement piece to your garden or yard. You do want to do a little research before you plant anything as some of the choices can be very finicky.
Jen is a master gardener, interior designer and home improvement expert. She has completed many home improvement, decor and remodeling projects with her family over the past 10 years on their 4,500 sf Victorian house. She is also a passionate farmer who keeps goats, chickens, turkeys cows and pigs on her farm, and an instructor for her community’s Organic and Sustainable Farming project.