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How to Grow Purple Hyacinth Bean Vine

Learn how to grow purple hyacinth bean vine, and add this vigorous ornamental vine to your garden. Beautiful purple flowers and striking pods add beauty and interest. 

Originally from tropical India and China, these vigorous vines quickly cover a fence or trellis, and the blooms are gorgeous in the fall. Also called “Jefferson Beans”, purple hyacinth bean vine was first planted at Monticello in 1804. It is still featured in Thomas Jefferson’s Monticello kitchen garden.

How to Grow Purple Hyacinth Bean Vine​

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5 Tips for How to Grow Purple Hyacinth Bean Vine

How to Grow Purple Hyacinth Bean Vine​

These tips are all you need to learn to grow purple hyacinth bean vine.


1. Plant purple hyacinth bean vine at the right time

How to Grow Purple Hyacinth Bean Vine​

Grown as a perennial in zones 10-11, purple hyacinth bean vine loves the heat. In cooler zones, it is grown as an annual from seeds planted in the spring.

Not an actual bean but a member of the pea family, purple hyacinth bean vine does best seeded directly in the garden if possible.

How to Grow Purple Hyacinth Bean Vine​

Plant when temperatures warm in the spring and nights are above 50℉. Plant hyacinth bean seeds 1 inch deep and 6 inches apart. Soak seeds for 6-8 hours before planting to speed germination.

If the weather gets too cold, the plants will slow or stop growing until temperatures warm. In cooler climates, start seeds indoors (a few weeks before planting), but do not let plants get too large before planting outside.  

How to Grow Purple Hyacinth Bean Vine​

 Plant in the low desert of Arizona from the middle of March through the end of May.


2. Choose a sunny spot for purple hyacinth bean vine

While generally low maintenance, purple hyacinth bean vine requires moist, well-draining soil in a sunny location. The vine is more susceptible to fungal diseases when grown in partial sun, and roots will rot in overly wet soil. 

How to Grow Purple Hyacinth Bean Vine​

Plants grown in full sun have more blooms and more vigorous vines. Otherwise the plants are relatively pest and disease free.


3. Give the vines something to climb

The roots of purple hyacinth bean vine are close to the surface and do not like to be disturbed; put trellises and supports in place at time of planting. Vines can climb up to 16 feet in only a few months. Just a few plants will cover a trellis, fence, or arbor.

How to Grow Purple Hyacinth Bean Vine​

The vines may need some guidance finding the trellis, but once there, they will twine and wrap easily around, up, and maybe back down again.


4. Be patient waiting for blooms to appear

The vigorous vines grow quickly, but flowers often wait until mid-summer to make an appearance. You’ll be rewarded for your patience with profuse bloom sprays on stalks growing out from the vines.

How to Grow Purple Hyacinth Bean Vine​

Flower clusters resemble pea blossoms and are followed by distinctive leathery-looking purple pods.


5. Harvest seeds to share and plant next year (but don’t eat them)

Although purple hyacinth beans are consumed in several parts of the world, preparation is tricky (due to the toxic levels of cyanogenic glucoside).

How to Grow Purple Hyacinth Bean Vine​

Leave the eating to experts, and save seeds at the end of the season to plant next year and share with friends.


How to Grow Purple Hyacinth Bean Vine​

You’ll know the seeds are ready to harvest when the pod changes from bright purple to silvery purple and the beans are plump and firm.


If this post about how to grow purple hyacinth vine was helpful, please share it:

How to Grow Purple Hyacinth Bean Vine​

Debbie J

Thursday 5th of October 2023

My friend says to leave the harvested bean pods unopened until spring. Everything I have read says to remove the seeds from the pods, let them dry and put in paper envelopes over winter. Does it matter?

Angela Judd

Sunday 8th of October 2023

No, it doesn't matter. I would make sure the pods have fully dried before you remove the beans. I like to store my seeds in a paper sack while they continue to dry to prevent mold. You can learn more here: https://growinginthegarden.com/how-to-save-seeds/

KCharbonneau

Monday 25th of September 2023

For the first time in over 10 years, my hyacinth bean plant did NOT BLOOM! It grew and grew nice and tall, but I never had any flowers on it. I had shared the seeds, from my plant the year before, with my daughter...her plant climbed up and around her outside stairs, but also NO BLOOMs. Does anyone have an idea what caused this? Thanks.

Angela Judd

Monday 25th of September 2023

If it's still growing, it may still bloom. My blooms just started this year.

Connie

Saturday 9th of September 2023

Where can you buy the seeds

Angela Judd

Monday 18th of September 2023

Renee's Garden Seeds has them.

Melinda

Tuesday 5th of September 2023

Any tips for vase life? They are beautiful in arrangements.

Angela Judd

Monday 18th of September 2023

To harvest for the flowers, harvest when 80% of flowers on stem are open. For the pods, harvest when 1/2 on stem are shiny and firm to touch. You can also use the tips in this blogpost for more cut flower tips: https://growinginthegarden.com/quick-and-easy-garden-flower-arrangements/

jane

Monday 31st of October 2022

Comment: A friend shared a single purple hyacinth bean and the result was just amazing. I have saved the pods and hope to plant several in the same spot for better trellis coverage next year. Question: Should I be guiding the vines to get better coverage High & Low? Question: Could it be that "dear" find the flowers as a desirable food source? One day I had flowers galore and the next it seemed something had eaten every flower it could get to.

Thank you!

Angela Judd

Monday 7th of November 2022

The vines will climb independently but can use help if you want them to climb a particular area. I am not sure if deers avoid them or not. Deers will eat most things if hungry enough.