Black Eyed Susan Vine: How to Grow Black Eyed Susan Vine
From its name alone, black eyed Susan vine is striking. However, there’s more to it than its blooms’ black cores (or so-called eyes). With its cheery petals and creeping nature, it’s a pleasant addition to your landscape.
This vine is a fast-grower. However, I learned from experience that this may turn out as a disadvantage if you’re not guarding where it crawls. Even so, it’s great that it’s sturdy and easy to cultivate.
Better known as black-eyed Susan vine, Thunbergia alata is well-loved for its flowers that bloom all throughout its growing season.
As a perennial, this vine can last for more than 2 years, unlike annuals and biennials. In tropical regions, it’s likely to keep on blooming several weeks after it grows and until it dies.
However, in temperate regions, it may die during the fall and winter seasons. Then, it may grow and bloom again when it’s spring and summer. After all, the rootstock can survive the cold seasons, and will regrow when it gets warmer.
The vine may also be grown as an annual. This means you can let it complete one growing season, which starts from seed germination to seed production. Afterwards, you can keep the seeds and remove the plant.
Like other flowering vines, T. alata is cultivated alongside other ornamental plants in an outdoor garden. Gardeners often set trellis next to the plant to help control and support its growth.
Letting it climb on your gates and walls is another way of making the most out of its creeping nature.
While challenging, it’s possible to tap this ornamental as a houseplant. You can have it in a pot along with a simple trellis.
You may also put it on a hanging basket. This prompts the stems to creep and cascade down.
Putting it indoors is not that ideal though. If you like it as a houseplant, you can place it on your deck or windowsill. Set it where it has access to full sun (or artificial light) at least 6 hours a day.
Keep in mind that the name black-eyed Susan isn’t exclusive to this vine. Another wild flowering plant has the same name, but it’s not related to Thunbergia alata. Both just have blooms with dark-colored centers.
Rudbeckia hirta, more commonly known as black-eyed Susan, is a member of the sunflower family and a native plant in North America.
Facts About Black-Eyed Susan Vine
Black-eyed Susan vine belongs to the acanthus family (Acanthaceae). Many species of flowering vines, herbs and shrubs form part of this group.
Plants under this classification are dicotyledons or dicots. Basically, they have two cotyledons. Cotyledons are the embryonic leaves inside their seeds.
They’re also distinct for having perfectly symmetrical flowers.
Majority of these plants thrive in tropical regions.
Lollipop plant, snapdragon root and Chinese violet are other plants in the acanthus family, but they’re under a different genus. Genus refers to the scientific classification of living things right under family.
Plants under the Thunbergia genus are also known as clockvines. Under this genus, you have bush clockvine, orange clockvine and blue skyflower in addition to black-eyed Susan vine.
Their blooms are very much alike as they all have five petals each. However, the black-eyed Susan vine’s flowers stand out the most for their dark centers. The others have seemingly hollow cores which are usually lighter in color. As for orange clockvine, its flowers, including their centers, are entirely bright orange.
T. alata is a native plant of African countries namely Botswana, Burundi, Congo, Côte d'Ivoire, Eritrea, Eswatini, Ethiopia, Kenya, Liberia, Malawi, Mozambique, Niger, Nigeria, Rwanda, Sierra Leone, South Africa, Sudan, Tanzania and Uganda.
Over the years, it was introduced to other African countries such as Mauritius and Seychelles.
The vine further spread and became naturalized in other continents. It thrived particularly well in Asian and South American countries mainly because of the similar climate to its original environment in Africa.
In India, the vine is even called scarlet clock while in Lesser Antilles, it’s referred to as golden bells.
Black-eyed Susan vine grows well in warm climate. The plant isn’t very picky in terms of soil and moisture. It doesn’t like very dry conditions though.
Black-eyed Susan vine is herbaceous, which means it doesn’t have woody stems. With its soft stems, you can easily guide its growth on your preferred supporting structure. Additionally, such stems are easier to cut.
In its natural habitat, T. alata can extend up to 20 feet. When potted, its height is less than that. Furthermore, it may only grow around 3 to 8 feet in the temperate regions.
The average height may also differ from one variety to another.
This vine’s leaves are also interesting for looking like arrowheads or elongated hearts. Each leaf can grow up to 3 inches. They’re notably coarse, too.
They are covered in soft and tiny hairs. While the plant is generally non-toxic, the hairy leaves may cause some skin irritation.
The leaves come in pairs but they tend to grow opposite each other.
Black-eyed Susan vine has winged petioles. (A petiole is the stalk that links the leaf to the plant’s stem.) The term alata in its scientific name is deemed to be a reference to such petioles. In Latin, alatus means winged.
Having winged petioles is one of the distinct features that differentiate this vine from other Thunbergia species.
Typically, each flower has five overlapping, heart-shaped petals with a dark spot in the middle.
From afar, the blooms resemble daisies but with different colors. When you come close though, the flowers of black-eyed Susan vine appear to have fewer but bigger petals.
You can find a pair of two leafy bracts at the base of each flower.
The vine is well-known for having brightly orange petals and dark-colored cores. The cores may appear dark brown or purplish brown in color.
However, you can also find varieties that have red, red-orange, yellow or white petals. Some may not even have the distinct dark eyes.
Its soft stems are usually green in color. The old ones may turn out to be dark green or brown though.
Varieties of Black-Eyed Susan Vine
Black-eyed Susan vine has more than 10 varieties. Some of the most popular ones are as follows:
If you’re into blooms with hints of fragrance, you might want to get the Angel Wings variety of black-eyed Susan vine.
This variety is named after its white flowers that bear the same supposedly purity of seraphs’ wings.
However, it’s worth noting that it’s not the only variety with white blooms. Pure White is another black-eyed Susan vine variety that has white blooms as its name suggests.
As featured in postcards and travel photos, African sunsets are well-known for looking warm and vibrant. Contrasting that bright orange sky is silhouettes of animals and/or trees.
The African sunset variety of black-eyed Susan vine will remind you of such scenery. Its blooms are dark red-purple after all. Instead of black or dark brown, its blooms have burgundy cores.
If you’re into the pastel trend, you might like to have the Spanish Eyes variety of black-eyed Susan vine. Its blooms come in shades of apricot and peach.
This variety is dubbed as superstar for a couple of reasons: the flowers have brighter shade and bigger petals.
There are other orange black-eyed Susan vine cultivars, too. Orange Wonder is also noteworthy because apart from its bright orange petals, it doesn’t have the typical dark centers.
If you’re after the most colorful blooms, Susie Mix is the way to go. As its name implies, it has white, yellow and orange flowers. Some have dark centers, while others don’t.
For a more colorful garden, you can grow different varieties of black-eyed Susan vine. Aside from the abovementioned varieties, you might also want to check out Beauty Spots, Bright Eyes, Canary Eyes, Salmon Shades, and Sunrise Surprise.
How to Grow Black-Eyed Susan Vine
Whether you’re a beginner or a long-time gardener, black-eyed Susan vine might be an easy plant for you to grow. Perhaps, the biggest challenge is to make sure it doesn’t creep into places where you don’t want them to.
If you’re a first-timer, you can choose to focus cultivating this plant alone. Anyway, it can creep into and occupy an area within several weeks. That might be too much for you to look after.
If your idea of a beautiful garden is thick vegetation, this vine may help fulfill that. In case you like something carefully manicured, you should prune on a regular basis.
In some parts of the world, the vine is treated as a pest because it’s invasive. Regular pruning also helps ensure that it won’t outgrow other ornamentals that you might have.
This vine is best grown in well-drained soil. Use loam but as much as possible, add some humus and sand.
The ideal soil pH level for this vine ranges from 6.8 to 7.7. This range is fairly neutral. Yet, you can still cultivate the vine in a slightly acidic or slightly alkaline soil.
Black-eyed Susan vine prefers to have full sun exposure. Take this into consideration, especially if you want the potted plant within your deck or beside the window.
It needs at least 6 hours of direct sunlight per day. If this isn’t possible, partial shade may do, but the growth won’t be as good as that with full sun.
Temperature & Humidity
There’s no specific temperature range ideal for this vine’s growth. If you live in an area with cool climate, however, make sure the temperature is over 60 degrees Fahrenheit.
You should also keep that in mind if you’re going to plant indoors.
Another option is to treat them like annuals. To do so, remove the vines before winter strikes or after one growing season.
Humidity doesn’t affect the vine that much. However, you have to ensure that its soil remains moist during very dry conditions.
The vine doesn’t like very dry soil. Yet, it doesn’t want a muddy one either.
In areas with warm climate, watering once every day or two should be enough.
It’s also advisable to apply mulching. The mulch helps retain moisture. This is especially vital in very dry seasons.
Mulch could either be organic or inorganic. As much as possible, choose organic mulch such as bark chips, grass clippings, ground corn cobs, leaf mold and pine needles.
For speedier growth and more bountiful blooms, applying liquid fertilizer to your black-eyed Susan vine is highly recommended. You can do so every two weeks starting from springtime.
When it comes to fertilizing, keep in mind the big 3: nitrogen phosphorus and potassium. Also dubbed as NPK, these three elements help strengthen the plant’s roots and protect it from extreme temperatures.
Many liquid fertilizers already have the said plant nutrients. If you can’t get the mixed ones though, you can buy them separately. When blending them, you can keep equal amounts. You don’t need specific ratios as the vine is sturdy on its own.
To apply liquid fertilizer, get a gallon of water. Next, dilute 1 ½ teaspoon of liquid fertilizer. Lastly, pour the water with the diluted fertilizer over the base of your black-eyed Susan vine.
Avoid applying excessive amounts or fertilizing frequently though. If you do any of these, you’ll end up with black-eyed Susan vine with more stems and more leaves but with fewer blooms.
Damaged roots and brown leaf margins are two signs of excessive applications of fertilizer.
In case you leave the rootstock outdoors during winter, you may pour diluted liquid fertilizer twice or thrice.
Aside from liquid fertilizer, you can tap compost as well. This can serve as organic mulch. At the same time, it can provide plant nutrients.
Before you put compost or any other organic mulch, remove the weeds near your black-eyed Susan vine. Then, apply 2 to 4 inches of organic mulch around the base of your vine.
If for retaining moisture, putting the mulch is best done before the warm season starts. If for keeping the rootstock warm, do it a week or two before winter.
Pruning keeps your vine in check. By pruning them regularly, you can ensure that the stems won’t intertwine that much. Additionally, you can prevent them from becoming too heavy for the supporting structure.
Light pruning can also improve the number of blooms.
You should prune on the early weeks of spring as new growth tends to occur during the latter weeks of the season and every summer.
As it’s soft-stemmed, you’ll only need hand pruners for this task. Wear gloves to avoid skin irritation while pruning.
To start, inspect your vine for any dead, diseased or dried stem. Using your hand pruners, remove these problematic stems afterwards.
Next, search for suckers. These are vertical growth near the roots and on the lower stem of your plant. Get rid of these undesirable growths, too.
Does your black-eyed Susan vine still appear too thick for your liking? Go over the healthy stems. Look for the older stems. These are usually brownish or darker green in color. They’re a bit harder and less hairy, too.
Be careful when removing older stems that have intertwined with newer ones.
If you don’t want the vine to grow in random areas in your garden, collect the garden waste in a bin before disposing.
Propagating refers to producing new plants. Beside seeds, you can do this task using leaf, root and stem cuttings from a living plant. Grafting is another option, but this is more ideal for plants with woody stems.
As for black-eyed Susan vine, you can tap seeds and stem cuttings. Between the two, using the latter is more advisable for beginners. The vines grown from seeds are much sturdier though.
Seeds are probably your only choice if there are no black-eyed Susan vines in nearby nurseries or within your neighborhood.
Each seed is approximately 4mm in diameter. To prepare the seeds, soak them in clean water and leave them overnight. This increases the chances of sprouting.
To propagate from seeds, you have to prepare a growing medium first. It doesn’t have to be complicated or expensive.
Seed germination is better done indoors than outdoors. This way, the sprouting rate will be higher.
When planting directly to the soil, you just have to scoop a bit of dirt. Make a ½ inch hole into the soil then cover it.
Seeds usually sprout 10 to 14 days after germinating them. In case you’re in a place with a cooler climate, seed germination may take up to 20 days.
If you choose to propagate from cuttings, the best way to do so is after winter. If you have access to the plant, whether you own it or you know someone who does, you can overwinter a healthy black-eyed Susan vine.
Afterwards, cut around 7 to 10 inches from the terminal end of the plant. Then, remove the leaves at the bottom of each cutting. Place the cuttings on a glass filled with water later on. Change the water every two days or once it becomes foggy. Keep doing so until the cuttings grow roots.
The next step is to plant them to the soil.
To further guide their growth, you can tie the young stems into the trellis.
When mites, whiteflies and scales infest your black-eyed Susan vine, you can treat it using neem oil or horticultural soap.
It’s worth noting that the plant can grow from root cuttings, too.
Moving the plants from one medium to another requires utmost care.
When you prefer your ornamental black-eyed Susan vine in your garden trellis outdoors, you don’t have to transplant it. You can simply treat it as an annual. However, if you like to keep it for few more years, you should consider transplanting.
You can transplant the vine when the temperature warms up. Make sure there’s no frost.
To transplant, you have to prepare a pot or planter. As for the size, it depends on how old your black-eyed Susan vine is. If it’s more than a year old, consider those that are 8 to 10 inches tall and at least 8 inches wide.
Next, collect the same soil which your vine currently has. Use this to fill the pot or planter. Before transplanting, you can just fill at least 2 inches of soil.
Once done, trim your black-eyed Susan vine to a height that you can accommodate indoors. If you don’t want it to creep out of the pot, prepare a simple trellis, then dig around the base of your vine. This way, you can ensure that you can keep much of the plant’s root system. You can bring some of the soil attached to the roots as well.
After that, hold the plant by its base and its main root. Transfer the vine into the pot. Keep holding the main root and stem as you fill the pot with additional soil.
Lightly press the soil to secure the plant in its place. Make sure the entire root system is covered with soil.
Slowly water the roots afterwards. As the soil compresses, add a bit more on the top. Another option is to top it with compost or another organic mulch.
For its stem, tie a few parts to a simple trellis. You can choose to let it cascade down, too.
Black-Eyed Susan Vine Health Benefits
In terms of health benefits, the vine’s roots deserve more attention than any other part.
You can take its fresh root extract as an aphrodisiac. This is what Indians do.
One study also suggests that the vine’s stem and leaf has antibacterial properties. It seems that it’s beneficial against Pseudomonas aeruginosa and Salmonella typhi.
Uses of Black-Eyed Susan Vine
While it’s mainly grown as an ornamental plant, black-eyed Susan vine has other uses.
Some vines under the acanthus family are used for managing mild conditions. One of such plants is black-eyed Susan vine.
In some areas in Eastern Africa, its leaves are collected and placed on the forehead as a natural remedy for headache.
Many kids in Eastern Africa play with the blooms. The flowers are charming and non-toxic anyway.
If you want to attract butterflies in your garden, this ornamental vine is also a great option. Besides butterflies, it draws bees as well. The nectar in its blooms is a huge delight for these bugs.
In horticulture, the vine can be grown to hide ugly surfaces, to thrive as natural groundcover or to serve as screens.
Black-eyed Susan vine makes a garden look lovelier with its eye-catching blooms. It’s highly recommended for those who have no gardening experience. If you like to set up decorative trellis or have a stunning wall, this ornamental plant may suit your needs.
Frequently Asked Questions
Is black-eyed Susan vine edible?
In some places in Africa, its leaves are harvested, cooked and eaten like other leafy vegetables. They’re not that palatable though.
How long do black-eyed Susan vines live?
As mentioned before, this vine can live for more than a couple of years in tropical regions. In temperate regions, it will either regrow in the warm months or only last for one growing season.
Can black-eyed Susan vine grow in pots?
The short answer is yes. However, keep in mind that it’s a vine. As such, it’s bound to creep out of the pot.
When shopping for planters, you can disregard intricate designs. The crawling stems are bound to cover them anyway.