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5 Easy-to-Grow Tropical Vines With Dazzling Blue Flowers

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The author lives in a quiet rural community in lower Puna on the Big Island. He's an avid gardener, traveler, and photographer.

Thunbergia battiscombei 'Blue Boy' has the most luxurious blue color.

Thunbergia battiscombei 'Blue Boy' has the most luxurious blue color.

Tropical plants usually have flowers with “warm” colors like red, orange, or yellow. There are only a few that produce blossoms in the shade of “cool” blue.

Here are five tropical vines with stunning blue flowers that could transform your garden into a chill-out Zen sanctuary! And they are super easy to grow!

Note: In temperate zones (with cold/snowy winters), these tropical vines can be grown as annuals. You may plant them in the ground or containers and make sure that they get plenty of sunlight and water.

Thunbergia grandiflora variegata with its fancy variegated leaves and exquisite blue blossoms.

Thunbergia grandiflora variegata with its fancy variegated leaves and exquisite blue blossoms.

1. Thunbergia (Thunbergia grandiflora)

Thunbergia (also known as Bengal Clock Vine, Blue Sky Vine, Blue Trumpet Vine) is a fast grower: the vine can grow up to a foot (30 cm) a day! Native to Southern Asia's tropical regions, Thunbergia blooms prolifically, producing large royal blue flowers in pendulous clusters.

This vine can grow in any soil type, but it does require full sun for flowering. During dry weather, water the plant regularly to prevent wilting. It is best to let it grow on a pergola or patio gazebo and enjoy a profusion of gorgeous blue flowers dangling overhead!

In many tropical places, including Hawaii, Thunbergia can become an invasive pest, escaping into the wild and taking over an entire forest!

Some cultivars produce attractive variegated leaves. Thunbergia ‘Blue Boy’ is known for its velvety cobalt blue blooms. Black-eyed Susan is also a Thunbergia species but with orange or yellow flowers.

 Blue Butterfly Pea is also called Asian Pigeonwings, Blue Bell Vine, or Darwin Pea.

Blue Butterfly Pea is also called Asian Pigeonwings, Blue Bell Vine, or Darwin Pea.

2. Blue Butterfly Pea (Clitoria ternatea)

Originated from Southeast Asia, this plant belongs to the legume Fabaceae family. Its butterfly-shaped flowers have bright indigo blue petals with a creamy white center. The pretty flowers bloom in the morning and last only one day. After flowering, small peas develop and mature into edible pods about 2-3 inches long.

In Thailand, Vietnam, Indonesia, and India, Blue Butterfly Pea flowers are eaten fresh or used as a natural food coloring in desserts (blue sticky rice) and drinks. Dried flowers and leaves are popular ingredients in many traditional Asian herbal remedies.

Quickly grown from seeds (germination takes 8-10 days), this fantastic vine needs something sturdy to trail on. Bamboo stakes, bean trellises or tomato cages are ideal! It makes a wonderful companion to other plants in a vegetable or herb garden.

A few glorious blue Morning Glory varieties.

A few glorious blue Morning Glory varieties.

3. Morning Glory (Ipomoea sp.)

Morning Glory belongs to the Convolvulaceae family and is closely related to sweet potatoes. Native to tropical regions of South America, this fast-growing vine is a must-have for many gardeners, beloved for its heart-shaped leaves and cheery, vibrant flowers. Morning Glory 'Heavenly Blue' is everyone's old favorite; however, new cultivars produce fascinating bicolor or tricolor blooms in all shades of blue!

Young seedlings will sprout from seeds sown directly in the ground under a trellis or arbor. The twining vines will quickly climb up and produce masses of flowers that attract butterflies, bees, and hummingbirds.

Morning Glory prefers full sun and can tolerate poor dry soils. It also does well in containers or hanging baskets.

Blue Passionflower unleashes its intoxicating scent at night to lure pollinators.

Blue Passionflower unleashes its intoxicating scent at night to lure pollinators.

4. Passionflower Vine (Passiflora sp.)

Passionflower Vine is native to South America and now growing in many parts of the world. Its blossoms resemble sea anemones and often possess a heady fragrance. Some cultivars produce magnificent flowers with mesmerizing blue petals and filaments. On cloudy or rainy days, their color may change from blue to purple!

Passionflower Vines are tenacious climbers; their long tendrils seem to have “eyes” – will reach out in certain direction to grab hold of whatever they "see"! In warm tropical climates, this prolific vine will become invasive if left unchecked. Regular training and pruning are needed to keep it from growing out of control!

The heavenly scented flowers attract nocturnal moths for pollination. Some varieties produce delicious edible fruits – like the lilikoi passionfruit of Hawaii.

Blue Jade Vine with its unusual, exotic blossoms.

Blue Jade Vine with its unusual, exotic blossoms.

5. Blue Jade Vine (Strongylodon macrobotrys)

Also called Jade Vine or Emerald Vine, this remarkable plant is native to the Philippines' lush tropical rainforests. Best known for its showy, cascading claw-shaped flowers in luminous turquoise or blue-green color. Each flower cluster can get as much as 3-4 feet (1.5 meters) long and contain 70-80 buds and blossoms.

Like Blue Butterfly Pea, Blue Jade Vine belongs to the Fabaceae family. In Hawaii, the flowers are used to make the most intricate, most beautiful (and most expensive!) leis for weddings and special ceremonies.

Propagate from seeds or stem cuttings (dip in rooting hormone before planting). A young plant requires part-shade location, humus-rich soil, and constant watering. Once established, the vine is care-free and will quickly cover an arbor, rock wall, or garden fence.

Plumbago (also called Leadwort) thrives in hot and humid climates.

Plumbago (also called Leadwort) thrives in hot and humid climates.

Honorable Mention: Plumbago (Plumbago auriculata)

Plumbago is NOT a vine! However, this hardy herbaceous plant behaves like a vine because it will climb on whatever it can reach! If left undisturbed, it could grow 10-15 feet tall, weaving its long, thin woody branches into neighboring shrubs and trees.

Plumbago produces an abundance of lovely sky-blue colored flowers. The delicate, unscented, tubular blossoms release a sticky sap that repels ants and aphids!

Plumbago is native to South Africa and does well in both temperate and tropical climates. It looks spectacular on a garden trellis or arbor! There is a white-flowered variety that is equally charming. Planting blue and white Plumbago together will create an enchanted look for the garden, especially at dusk when the flowers seem to glow in the darkening evening light!

The plants featured in this article are from the lower Puna district (USDA Plant Hardiness Zone 12b) on the Big Island of Hawaii. All photos are taken by the author.

Close-up view of the irresistibly charming Thunbergia blossoms.

Close-up view of the irresistibly charming Thunbergia blossoms.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2021 Viet Doan

Comments

Viet Doan (author) from Big Island, Hawaii on March 29, 2021:

Aloha Mary! I love all blue-colored flowers. Wish I could plant blue Clematis or Forget-Me-Not here in Hawaii. They wouldn't stand a chance in this hot, humid, and rainy tropical weather, oh well!

Viet Doan (author) from Big Island, Hawaii on March 29, 2021:

Thank you Linda. So glad you enjoy the photos. I'm fascinated with blue-colored flowers of both tropical and non-tropical plant species.

Viet Doan (author) from Big Island, Hawaii on March 29, 2021:

Thank you Peggy. When I lived in Texas years ago, I had many ruby-throated hummingbirds buzzing around the morning glory hedge in my backyard. Wonderful nature!

Mary Norton from Ontario, Canada on March 29, 2021:

I haven't seen that blue jade vine before. I love vines in the garden. I have some success with passion and morning glory in the Philippines when I spend time there. It's nice to be in Hawaii where you can plant so many beautiful flowers.

Linda Crampton from British Columbia, Canada on March 27, 2021:

The flowers and your photographs are beautiful! Thank you for sharing the pictures and the information.

Peggy Woods from Houston, Texas on March 27, 2021:

I used to grow morning glories on a fence before we had planted other shrubs in our yard. It was so pretty! Some of the ones you featured here are very exotic in appearance.

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