Seeing any tree with beautiful blue flowers will be a breathtaking experience.
Blue flowers are scarce, but they do occur.
Whether you’re wondering which trees have blue flowers or are planning a beautiful colorful garden, look at those trees with blue flowers.
Related: Trees with Red Flowers | Trees with Orange Flowers
1. Blue Jacaranda (Jacaranda mimosifolia)
- Sun needs: The blue jacaranda tree needs moderate sun to grow. It will do best in an area that gets full sun for part of the day and shade for the remainder.
- Water needs: This tree prefers moist conditions and must be watered regularly, especially when it is first established.
- Soil needs: The blue jacaranda tree will do best in a rich, sandy loam that drains well.
- Soil pH: The ideal pH for the blue jacaranda tree is between 6.0 and 7.0
- Hardiness zone: The blue jacaranda tree is hardy in zones 9 to 11
The blue jacaranda tree grows in the tropical and subtropical areas of South America, Mexico, and the Caribbean. These regions are commonly known as the “bluebell tree.” It can also be found in Florida, California, Texas, and Hawaii in the United States. The blue jacaranda typically reaches a height of 30 to 40 feet (9-12 m). It has a long flowering season that lasts from spring to summer. The best time to prune this tree is after it has finished blooming.
This fast-growing tree does best in full sun but can tolerate partial shade. It prefers well-drained soil and is drought tolerant once established. The blue jacaranda has a moderate salt tolerance and can be found growing near the coast. It is hardy in USDA zones 9-11.
This native to Brazil is imported in many areas due to its beautiful, bright blue and violet foliage.
They were discovered in South America, deep in the forests of Brazil.
William Nelson, a local tree entrepreneur, took six months to plant the trees in the Kensington suburbs in the 1880s.
Pretoria and Johannesburg have the most of these trees. They can also live for up to 200 years. Pretoria is currently nicknamed “Jacaranda City.”
In particular, they are part of the culture of South Africa, where they were imported in the 1830s.
You will also see many jacaranda trees in Mexico City. They were eventually planted in Peru. Two Japanese adventurers, father and son, Tatsugoro Matsumoto and Sanshiro Matsumoto, imported them to Mexico with their gardening business.
The trees can reach up to 20 meters or between 25-40 feet high and 15-30 feet wide. Their spreading crown of flowers looks beautiful anywhere you plant it. The flowers also have sweet nectar for the pollinators.
The tree has woody stems. The flowers have five lobes and grow in the shape of a bell. Its leaves are delicate and resemble ferns.
It requires minimal care and is resistant to disease. However, gardeners recommend not pruning the tree because it affects its natural shape.
They have a big cultural significance in Australia.
This evergreen tree favors zones 12, 13, and 15-24. They have a moderate rate of growth.
The blue jacaranda is a beautiful tree that will add a touch of color to any garden or park.
The tree itself also has many uses. For one, its wood is highly prized as logwood. It’s used to make charcoal, wood paneling, and fine furniture.
The flowers are also a natural dye and have been used in South American cultures for centuries.
The plant also has native medicinal properties. They were used in baths to treat skin wounds or acne. The leaves and bark are used to treat varicose veins and neuralgia.
There are many ways to cultivate Jacaranda. You can plant them from seed, and use cuttings or graftings. However, if you grow it from seed, it will take much longer than other methods. They prefer well-drained soil. They do best in full sun. Also, they can tolerate brief drought or freezing periods.
2. Blue Wisteria (Wisteria floribunda)
- Sun needs: varies
- Water: varies
- Soil pH: 6.0 – 7.0
- Hardiness zone: 7 – 9
Some horticulturists grow the weeping willow and the wisteria together. This produces a tree known as the Blue Chinese Wisteria.
Wisteria itself is a fast-growing vine. It is native to China, Korea, and Japan.
The vine can reach lengths of up to 30 feet, and the flowers can be up to 12 inches long.
The blue wisteria blooms in the springtime. The flowers are very showy and have a sweet fragrance.
The plant is easy to grow and is relatively disease resistant. It does well in full sun or partial shade.
Seeds, cuttings, or layering can propagate the blue wisteria.
The wisteria itself is a vine in the legume family. This may be why its beautiful blooms resemble pea flowers.
Another name for the wisteria is the “wedding vine.”
It was named by an English botanist, Thomas Nuttall. Its namesake is Dr. Caspar Wistar.
The Japanese wisteria spins its stem clockwise. Chinese wisteria twines its branches counterclockwise. In total, there are more than ten species of wisteria in the UK. The most enormous wisteria in the world is located in California. It is over 1 acre in size.
The weeping willow is a deciduous tree that is native to China. It gets its name from the long, drooping branches.
The weeping willow can grow to be quite large, with some trees reaching heights of up to 40 feet.
The weeping willow is very easy to grow and tolerant of different soil types.
The tree likes full sun or partial shade and needs lots of water.
seeds, cuttings, or grafting can propagate the weeping willow
3. Blue Rose of Sharon (Hibiscus syriacus)
- Sun needs: moderate
- Water: plenty
- Soil pH: 6.0 – 7.0
- Hardiness zones: 4 – 8
The blue rose of Sharon is a shrub that blooms in the summer. It is a fast grower and can reach a height of 6 feet. It prefers full sun but can tolerate partial shade. It is a trendy plant in gardens and parks due to its beauty. The blue rose of Sharon has long, drooping clusters of blue flowers that bloom in the summertime. The plant is easy to grow and is relatively disease resistant. Seeds, cuttings, or grafting can propagate the blue rose of Sharon.
The Blue Rose of Sharon is a bushy shrub in the Hibiscus family. It can be pruned and cultivated to grow like a tree by removing the bottom branches and allowing the plant to grow upwards.
The Blue Rose of Sharon is native to China and Korea. It has been introduced to many other parts of the world, including North America.
The flowers are very showy, and they are a beautiful blue color. The plants bloom in the summertime.
The Blue Rose of Sharon is easy to grow, and it is relatively disease resistant.
It can reach heights of up to 8-12 feet. Its spread reaches between 4-6 feet. This is a specialized cultivar that you can find in specific nurseries. So, many of them do not produce viable seeds.
It can be grown in a variety of soil conditions. This includes moist, organic soils with plenty of fertilizer. It is also a good landscaping plant. It tolerates heat, salt, humidity, and drought.
The flowers, leaves, bark, and roots of the Rose of Sharon have medicinal properties. To begin with, the flowers are often made into tea with a pleasant, sweet taste.
Scientific studies show that making this plant helps reduce blood pressure.
Some people use the flowers and bark to make a hair rinse. It is shown to help with hair growth.
4. Blue Butterfly Bush (Buddleja davidii)
- Sun needs: moderate
- Water: plenty
- Soil pH: 6.0 – 7.0
- Hardiness zones: 4 – 8
The blue butterfly bush (Buddleja davidii) is a shrub in the family Scrophulariaceae. It is native to China but has been introduced to many other parts of the world, including North America and Europe.
Another name for this plant is “Blue cat’s whiskers.”
The flowers are a beautiful blue color and bloom in the summertime.
The plant is easy to grow, and it is relatively disease resistant.
Seeds, cuttings, or grafting can propagate the blue butterfly bush.
It can reach heights of up to 10 feet.
The blue butterfly bush prefers full sun and well-drained soil. It is tolerant of a wide range of soil types, including clay.
The blue butterfly bush is a very popular landscaping plant. It is often used as a hedge or in butterfly gardens.
This plant likes pruning, and you can make it into your desired shape. When left unpruned, its spread can exceed 10 feet.
The blue butterfly bush has many medicinal properties. The leaves, flowers, and stems can all be used to make teas. These teas have many health benefits, including reducing anxiety and helping with digestive problems.
They are related to other blue flowers, like mint or lavender. However, their prolific blue flowers make them more similar to a tree. Also, it is an evergreen. They produce flowers from spring to autumn.
The blue butterfly bush can grow to heights of up to 15 feet. Its large, significant branches and brushes make it a highly desired plant in many parts of the country.
They grow their best in tropical and subtropical climates. Also, they are well suited to greenhouses.
5. Rhododendrons
- Sun needs: this varies by plant
- Water: plenty
- Soil pH: 5.0 – 7.0
- Hardiness zones: 4 – 8R
Blue rhododendrons are a prize to come by. This hearty bush is also called an azalea. It is a part of the Ericaceae family. The name “rhododendron” means “rose tree” in Greek.
It reaches heights of anywhere from six to ten feet. They have broad leaves and beautiful trumpet-shaped blooms.
The plant is native to Europe, Asia, and North America. It was introduced to England by explorers from the Alps. If you prune it to be single-stemmed, you can create a tree-like shape. The most enormous giant rhododendron tree in the world is in England. It is more than 120 years old and measures more than 50 feet.
The blue rhododendron is easy to grow and is relatively disease resistant.
Seeds, cuttings, or grafting can propagate the plant.
Rhododendrons prefer full sun and moist, well-drained soil. They are tolerant of a wide range of soil types, including clay.
This bush is native to Europe, Asia, and North America. It can be found in woodlands, heaths, and bogs. The blue rhododendron has many subspecies that vary in color from white to pink to purple and, of course, blue.
The blue rhododendron blooms in late spring or early summer. The flowers are very showy and they grow in clusters.
The blue rhododendron is easy to grow and is relatively disease resistant.
Rhododendrons prefer full sun and moist, well-drained soil. They are tolerant of a wide range of soil types, including clay.
This bush can also be used in informal gardens and naturalized areas.
The blue rhododendron has many medicinal properties. The leaves, flowers, and stems can be used to make teas. These teas have many health benefits, including reducing anxiety and helping with digestive problems.
6. Lignum Vitae (Guaiacum sanctum)
- Sun needs: moderate
- Water: once a week
- Soil pH: 5.0 – 7.0
- Hardiness zones: 9B – 11
This shrub is a flowering plant that is part of the Zygophyllaceae family. The lignum vitae is native to the Caribbean, Mexico, and Central America. It can also be found in South America, Florida, and Texas.
Lignum Vitae translates to the wood of life. They were used to create a medicine to treat diseases like arthritis.
The lignum vitae tree is a part of the family Verbenaceae.
The lignum vitae tree can reach heights of up to 100 feet. It has dark green leaves and small, yellow flowers. The wood is hefty and dense. It is used to make products like pool cues and cricket balls.
The lignum vitae tree prefers full sun and well-drained soil. It is tolerant of a wide range of soil types, including clay.
The tree is not commonly used as a landscaping plant because it is slow-growing and complex to transplant.
However, wood is precious and is often used for carving.
The lignum vitae tree has many medicinal properties. The bark and leaves can be used to make tea to treat fevers and colds.
The tree is also used in traditional medicine to treat arthritis and other joint pain.
The tree itself is endangered, as it was overcultivated due to its medicinal properties.
7. Texas Mountain Laurel (Sophora secundiflora)
- Sun needs: minimal
- Water: once a week
- Soil pH: 5.0 – 7.0
- Hardiness zones: 8B – 10
The Texas mountain laurel is a flowering shrub that is part of the Fabaceae family. The plant is native to the southwestern United States and northern Mexico.
It can also be found in parts of Texas, Oklahoma, Colorado, and New Mexico.
The Texas mountain laurel is a member of the pea family.
The Texas mountain laurel can reach heights of up to 30 feet. It has dark green leaves and clusters of small, purple flowers. The flowers are very fragrant, and they bloom in the spring.
The Texas mountain laurel prefers full sun and well-drained soil. It is drought tolerant, but it will not tolerate wet conditions.
This plant is often used as a landscaping plant because it is relatively easy to care for and i,t is drought tolerant.
The Texas mountain laurel is poisonous to humans and animals if ingested. All parts of the plant are toxic, but the seeds are the most dangerous.
What is the rarest color for flowers?
The rarest color for flowers is blue. Blue flowers are uncommon in nature and can be challenging to find. A few blue flowers are available, but they are usually found in artificial settings like gardens or florist shops.
Why are blue flowers so rare?
The reason blue flowers are so rare is because of the way plants produce color. Plants produce color by using pigments, and there is no pigment that naturally produces blue. Instead, plants that appear to be blue have adapted to produce other colors that combine to give the illusion of blue. For example, some plants have white flowers with a blue tint. Others have violet flowers with a yellow center.
While blue flowers are very rare in nature, you can find them in artificial settings like gardens or florist shops. This is because growers can use genetic engineering to create plants with blue flowers.
Sources:
UC Davis – Department of Plant Sciences