Caren White is a Master Gardener and instructor at Home Gardeners School. She has been associated with Rutgers Gardens for over a decade.
I’m always on the lookout for new (to me) and interesting plants for my garden. My most recent find is the purple bell vine. I love the interesting flowers.
What is Purple Bell Vine?
Purple bell vine (Rhodochiton atrosanguineus) is a flowering vine that is native to Mexico. It was introduced to the rest of the world in 1836. Because it is native to Mexico, it needs warm temperatures. It is only hardy in zones 10 -12. The rest of us grow it as an annual.
The purple bell vine grows to 8 - 10 feet in length. The leaves are heart shaped, looking a lot like morning glory leaves but the two vines are not related. Like morning glories, the vines climb by twining around supports. Purple bell vine leaves are hairy, bright green and occasionally edged with burgundy. They are about two inches wide.
The flowers give the vines their name. They look like purple bells with maroon clappers. The vines bloom all summer through the fall until they are killed by temperatures below 40⁰F.
How to Grow Purple Bell Vines
Purple bell vine can grow in full sun or partial shade. They prefer afternoon shade, so an eastern exposure or anywhere in your garden that gets only morning sun is perfect. Give them rich, loamy well-drained soil. Keep the soil moist, about 1 inch of water per week. Fertilize with a slow release fertilizer or you can use a liquid fertilizer once a month. Whichever fertilizer you use, make sure that it is formulated for flowering plants.
Balanced fertilizers such as 10-10-10 don’t have enough phosphorous (the middle number) in them. Phosphorous helps plants produce flowers. The first number is the amount of nitrogen. Nitrogen helps plants produce leaves. That’s why fertilizer for your lawn usually has high nitrogen. If you put that fertilizer in your flower garden, your plants will grow to gigantic sizes but won’t have any or very few flowers. That happened to me once when my neighbor splashed his lawn fertilizer into my garden!
Be sure to give your vines something to climb on, usually a trellis, but you can use anything. I grow a lot of my vines on the ugly chain link fence that surrounds my backyard. That chain link fence is how the neighbor’s lawn fertilizer got into my garden.
If you are growing your vines in the ground, space them 10 – 12 inches apart. These vines can be grown in containers but make sure that you install a trellis in the container for them to climb on. They can also be grown in hanging baskets where they will drape downwards if they have nothing to climb on.
Because they like partial shade, these vines can be overwintered in your home. Our homes do not have as much sunlight as the outdoors, so only shade or partial shade plants will grow well indoors. Grow your vine in a container and bring it indoors in the fall when the night time temperatures start to go down to 40⁰F. You can bring your vine back outdoors in the spring when night time temperatures go above 40⁰F.
How to Grow Purple Bell Vine From Seed
Purple bell vines are most often grown from seed. You will need some patience. The seed takes a while to germinate. Start your seeds 12 – 16 weeks before your last frost date. Sow them on the surface of pre-moistened soil in a container. Don’t cover them. They need light to germinate.
I always moisten my soil before I sow my seeds because I have found that if I try to water after I have sown my seeds, both the soil and the seeds tend to float out of the container. So I water first, then sow my seeds.
Cover your container with a plastic bag to make a little greenhouse. Then place your container in a sunny window. The seeds can take up to 45 days to germinate. Once they have germinated, you can remove the plastic bag.
You can transplant your seedlings into your garden after your last frost when night time temperatures are above 40⁰F. Space them 10 – 12 inches apart or transplant into containers or hanging baskets.
© 2020 Caren White