This is a step-by-step guide on how to grow the stunning Thai blue butterfly pea flower from seed all the way to harvest.
What Are Thai Blue Butterfly Pea Flowers?
I started growing Thai blue butterfly pea flowers because the vibrant blue color caught my attention. I was looking for a perennial, flowering vine that had blue flowers to attract bees (bees are attracted to the color blue and yellow). Thai blue butterfly pea fit that bill and much more. I started learning about this unique flower that was not only beautiful, but has many health benefits and uses in the kitchen. The intense blue color is attributed to a high amount of antioxidants called anthocyanins. This is the same antioxidant that gives blueberries its deep blue color. The flowers are used to make a high antioxidant tea and many other beverages. The blue color is a great all natural food dye used to make colorful desserts, baked goods, and the famous Thai blue rice. Moreover, these flowers are pH sensitive, meaning the color is blue at a neutral pH and starts changing pink when it is exposed to something acidic. These color changing properties make for a fun experiment with kids and lots of people like to make a magic color changing lemonade with these flowers (my recipe is linked at the bottom of this blog).
Watch the video version of this grow guide on my YouTube channel.
Choosing the Right Cultivar
Although there aren't many varieties of Thai butterfly pea, the blue variety is the most popular. There are some other varieties that produce white or pink/lavender flowers. They are beautiful flowers but do not have the high levels of antioxidants like the blue variety.
When purchasing seeds you might notice some varieties described as "doubled" or having double the petals. The variety that I grow is the double petal variety with much fuller blooms than the standard single petaled variety.
Growing Conditions
Thai butterfly peas thrive in tropical climates. Hardy in zones 9 and above, these perennials do not like the cold. In my zone 10a garden, they bloom continuously in the warmer months, tolerating even the intense Florida full sun. These plants are not fussy, and grow well even in poor soils. Once the plant is established, I dont even water or fertilize them.
Planting Instructions
If starting from seeds, sow them indoors, 12 weeks before your last expected spring frost. Soak the seeds overnight to help soften the shell and speed up germination. Then sow the seeds in 4 inch pots filled with some fluffy seed starting mix. Put the container over a heat mat to keep the soil warm. Once the seedling sprouts, it will require a bright light source for the best growth. Transplant the seedling outdoors once all danger of frost has passed.
To transplant a seedling you grew from seed or maybe you're transplanting a purchased plant, create a mound with some compost. Make a hole at the center of the mound and mix in some fertilizer. An all purpose fertilizer like Espoma Garden Tone works best. Pop the plant into the planting hole, pat down the soil, and water it in. I like to plant it in a mound to elevate the root ball for better drainage especially since I am in Florida and our soils easily flood during the rainy season.
Care Tips
Thai butterfly pea plants grow best when the soil dries out a little bit before watering again. If you can throw some fertilizer its way about once a month, that would be great but established plants grow well without the added nutrients. They don't have many pest or disease issues either.
Occasionally I will notice the leaf edges are cut and rolled in which is caused by the caterpillar stage of the Long-tailed Skipper butterfly. I do not spray treatments to kill these caterpillars. The damage is never enough to actually affect my plants.
In humid conditions the plants might get some powdery mildew. If that happens, spray with 1 cup of hydrogen peroxide per gallon of water about once every 3 to 5 days until you notice the spread of the disease has stopped. Growing Thai butterfly pea plants vertically, like on a trellis helps to provide better air flow and prevent powdery mildew.
Harvesting and Using the Flowers
Thai butterfly pea plants typically begin to bloom about six months after being started from seed. For the best quality, harvest the flowers in the morning before they close. These vibrant blooms can be used fresh or dried for later use, with dried flowers offering a more concentrated color — meaning you’ll need fewer dried flowers in recipes compared to using fresh flowers. To dry the flowers, spread them out in a single layer on a clean kitchen towel, paper plates, or a large mesh herb dryer, and let them air dry for about two weeks. Once dried, you can grind the flowers into a fine powder using a high-powered blender, then sift out any larger particles. This powder is perfect for teas, recipes, or as a natural food coloring, allowing you to enjoy the beauty and benefits of butterfly pea flowers all year long.
I hope this guide inspires you to explore the joys of growing Thai butterfly pea flowers. Below are some of my recipes that use Thai blue butterfly pea flowers.
Recipes That Use Thai Blue Butterfly Pea Flowers
These are my recipes that use Thai blue butterfly pea flowers.
Thai Blue Rice Recipe HERE.
Blue Japanese Lemon Sour Drink HERE.
Magic Color Changing Lemonade HERE.