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Bolusanthus speciosus

Family: Fabaceae (Pea subfamily – Pod-bearing family)

Common names: Tree Wisteria (E); umHolo (Z); Vanwykshout (A);

Native to: Southern Africa
A graceful tree bearing large sprays of mauve flowers in spring.

Bolusanthus speciosus










5m x 5m


7m x 6m

Bolusanthus speciosus


An attractive deciduous tree which is stunning in spring when it is densely covered in drooping sprays of mauve, sweetpea-like flowers.   It has a rounded crown of weeping foliage.   The leaves are alternate, compound and glossy green.  The bark is rough, dark brown and longitudinally fissured.  The fruit is a flat, narrow pod that is borne in hanging clusters.

Bush veld and wooded grassland.
Attracts birds and butterflies.
Water moderately when young.
Low maintenance.
Protect young trees from frost.
This tree makes a lovely focal point in a home garden. It is well suited as a street tree, for office complexes and schools.
Bushveld, Country, Woodland
Clusters of pea-like mauve flowers are borne in loose terminal sprays up to 30cm long in spring.
The leaves are alternate, compound with up to 7 leaflet pairs and a terminal leaflet. Leaflets are lanceolate, shiny green above and duller below.
Dark brown to black, rough and longitudinally fissured.
A flat, narrow light brown pod that stays on the tree for about 4 months before splitting to release the seeds.
Easily propagated from seed. Sow seed in hot water overnight before sowing.

32 Responses

  1. Hi Lenn

    Thanks for visiting Plantbook.

    I think that lawn tends to be over-utilised as a groundcover solution for areas that are sometimes not ideal for lawn. The fact that your Kikuyu is dying back and being overrun by weeds is an indication that the conditions (such as increased shade and root competition) are longer suitable for Kikuyu. LM lawn may work but perhaps also consider creating a bedding area around the tree. This will introduce more variety and also help protect your tree from damage from an edge trimmer.


  2. Good day Glenice
    Thank you for the well laid out and user friendly Plantbook website.
    I now know understand why our tree has not yet flowered. Our tree is growing nicely but is only about eight years old and recieives full sun from mid morning to mid afternoon. The Kikuyu grass around the tree is dying back and a broad leef weed is encroaching. As this is the only lawn inside our Hartbeespoort property, I am now wondering if indeed a lawn will grow under and around it or if I should try LM grass or not?
    Your input will be welcomed.
    Kind regards

  3. Hi Norman

    Thanks for visiting Plantbook.

    It’s great to hear about our indigenous plants being given a home in exotic far-away lands.

    At 12 years old, they should have started flowering. As the foliage is healthy, it is likely that they are receiving too much water, particularly in the winter season. Bolusanthus speciosus is a deciduous tree that has a dormant period in winter which helps conserve the tree’s energy for the production of their magnificent spring flower display.

    We’ve found that indigenous plants work best in a garden setting where the conditions match those of the plant’s natural habitat. As they are naturally found in summer rainfall regions, they will have more prolific flowering if winter watering is completely stopped.


  4. Hi Glenice,
    I live in Bahrain and have grown Bolusanthus trees from seed which i brought from South Africa. Plants have grown well and are now 12 years old. Great foliage but have never produced flowers.
    Please advise what i should do.
    Many thanks

  5. Hi Salvatore

    Thanks for visiting Plantbook.

    Bolusanthus speciosus doesn’t need any additional watering when in flower. Where it grows naturally in the wild, there is generally little or no rainfall during the flowering period.


  6. Hi Salvatore

    Thanks for visiting Plantbook.

    The watering requirements of your tree will depend on the age and soil conditions. It sounds like you’ve still a young tree and it is normal for it to have only a few flowers in the first flowering season.


  7. Hi Glenice, We had 12mm of rain which gave us a bloom , we had no futher rain for the past 3 weeks , should we hand water our tree. it is not the begining of the wet season in Australia.

  8. Hi Cindy

    Thanks for visiting Plantbook.

    You’ve a wonderful climate which will work for many species. Bolusanthus speciosus is naturally found in your area so you should have no problems growing it in your garden.


  9. Hi Wilna

    Thanks for visiting Plantbook.

    Bolusanthus speciosus, like any tree, will have a limited lifespan and restricted growth when planted in a container.

    They do make interesting bonsai specimens though, so it will depend on your preferences.


  10. Hi Melanie

    Thanks for visiting Plantbook.

    This is quite common with many trees. They need to adjust to their new environment first and in the first few years the growth is primarily unseen as it is normally focused on establishing a root network.

    You probably fed and composted your tree when you initially planted it and that should be sufficient for the first year.

    Be patient and allow it time to settle.


  11. Ho,
    I bought my tree wisteria from Cape Garden in February this year. It has not grown in any way since then. Is this normal? We live in Stellenbosch and I’m keeping her in a huge container until her permanent spit is ready? Is there anything i can do to encourage growth?

  12. Hi Grace

    Thanks for visiting Plantbook.

    Bolusanthus speciousus can take 7-10 years to produce their first flowers so your tree may be reaching that age how, depending on the size of the tree when you bought it.

    Note that this species is not naturally found in the Cape so may take longer to adapt to the growing conditions.


  13. I have a Bolusanthus in my garden in Cape Town. It has grown quite tall with type of pony tail on top.I purchased it from Kirstenbosch as a sapling 5 years ago. It has never flowered. I have given the tree 232 and 315 for time
    to time should I feed it with anything else

  14. Hi Alta

    Thanks for visiting Plantbook.

    It sounds like you’ve taken all the necessary precautions with your trees and the frost protection may be sufficient. It is always risky to plant a tree that was grown in a different geographic location as it has adapted to that climate. Most areas in the Free State experience much colder conditions. Since Bolusanthus speciosus does not naturally occur in your area, not much is known about how it can tolerate those conditions. You’ll have to keep us informed on your success.

    The dry seed pods stay on the tree for a long period, so there is no need to remove them.


  15. Good morning
    I’ve purchased 2 (100L)Vanwykshout trees from a grower in Jo’burg & replanted in the spring. The climate should be fairly simmilar to the Free State’s. They are currently standing approximately 3,5m high. Appart from mulching over drip-zone, do I need to provide any extra frost protection? The first 1m up from soil level is covered by frost-covering, but that was done as emergency protection the cats scratching the bark to tatters.
    Second question: there is still profuse ammounts of seeds hanging in the trees. Should it be removed, or will nature take care of this?

  16. Hi Bryon

    Thanks for visiting Plantbook.

    The key for gardening in rocky soil is to prepare a wide planting hole and fill that with quality topsoil mixed with compost. The guide is to make the hole twice as wide as the rootball of your new trees. You could go wider if you wish. This will help provide a stable base for your trees to get established in their new home, thereafter, they’ll work their way through the rocks.


  17. Hi glenice
    We are building our house in Grabouw in the western cape which has very high rainfall and fierce north easterlies during winter.
    The plot of our house is huge and the front garden has about 300 square meters to play with.
    I intend to plant at least 6 trees which includes,cape holly,wild olive,ponpom,cheese wood, white pear and a cape chestnut
    The soil however is rocky
    Could you please assist with how to treat the soil before planting and also soil maintenance after planting?
    Trees are expensive and I’m very excited to have a beautiful garden so I want to get everything right from the outset
    Thank you

  18. Hi Sanette

    Thanks for visiting Plantbook.

    It sounds like your tree is still too young to start branching out. The growth of a tree in its early years is mainly in the roots and height. Remember, it is normal in a natural situation for the trees to grow taller than the surrounding plants in order to get more light.

    This could be the case with your tree. You’ll need to be concerned after 5 years if you don’t notice any lateral growth.


  19. Hi!

    I planted a wisteria tree in my garden about a year ago. We live in Botswana where it is very hot and dry and we have red sand for soil. The tree has grown about two meters, but never branched out. The leaves are only at the top meter (3rd) of the tree. I would like it to branch out because I want shade! What do I do?


  20. Hi Ely

    Thanks for visiting Plantbook.

    It would be interesting to know where you’re located. Does Bolusanthus naturally grow in your area, or did you “import” seeds from elsewhere?

    It seems that your Bolusanthus has grown very well. The tall growth could be a sign of competition with surrounding plants for light.

    At this stage, the foliage is probably helping to sustain the growth, so I would recommend that you avoid pruning it. Rather opt to stake the tree to help protect the trunk during your cyclone period.


  21. I planted the tree in a very tropical region and it has grown 3 m in two years from seeds with 2 m in the last 12 months. It did not seems to have any dormant period. Do you think it will flower? Since I have only one tree, I dont like to prune it, but it has only two branches and quite thin on a one meter truck. When we have the tropical cyclones in the next few months, I am concerned the thin two branches might just break or should I prune it?

  22. Hi Suzanne

    Thanks for visiting Plantbook.

    Your tree is likely to start forming a crown in the third year. As your tree is still new to your garden, most of the growth is probably taking place underground. Once the root network and trunk are established, then you’ll start seeing the canopy forming.

    I would recommend that you avoid removing the lower leaves as these feed the trunk. Removal of the side leaves tends to encourage a tall, thin trunk that cannot support the tree.


  23. We bought our bolsanthus from a reputable garden centre in Randburg a year ago. It has grown very fast but does not form branches, only single leaf bracts. I’ve removed the lower leaves from time to time but am not sure if I should trim the top to encourage side shoots. It’s about 2 meters tall. Looking forward to your feedback

  24. Hi Ian

    Thanks for visiting Plantbook.

    While Bolusanthus speciosus is not naturally found in the Cape, However, it has adapted to the environment, hence the availability in your local nursery.

    It should tolerate the winter rainfall as long as your soil is well-draining.


  25. I just planted a Van Wykshout which I bought at Stodels. When I asked them about whether it is a good idea to plant this tree in the winter rainfall area of Durbanville, Cape Town, the answer was that if it did not grow here they would not sell it. I am not convinced though, so what should I do to protect it during the winter months? I planted it right next to the vibracrete wall, and the house is 3 metres away, so it is kind of protected. It does only get a little bit of sun, but once above the vibracrete it will get sun a lot more. Normally we get a lot of rain in winter which we are extremely happy about after a long drought

  26. Hi Carl

    Thanks for visiting Plantbook.

    Oh, dear. Your tree is not happy about something in the environment.

    Some questions to help determine the cause:
    – Is your soil healthy? It could be a nutrient deficiency.
    – Does the plant look healthy?
    – Are you watering it continuously throughout the year? As Bolusanthus speciosus is deciduous, it prefers a dry winter to allow it to go dormant. If this does not happen, the tree usually cannot build the reserves to produce abundant flowers in spring.


  27. Hi There

    I have an 8 year old Tree Wisteria tree which I grew from seed.

    It’s probably 2m tall now.

    At what age will it start to bloom?

    Thank, Carl

  28. Hi Vanessa

    Thanks for visiting Plantbook.

    Bolusanthus speciosus (Tree wisteria) needs little pruning. But if you wish to encourage a more bushy form, then do so once a year in summer.

    As it is a deciduous plant and goes dormant in winter, avoid watering it in winter. This mirrors the plant’s natural habitat and tends to encourage more flowers.


  29. This is a lovely article – really interesting.

    Please can you advise – When is the best time to prune a tree wisteria (bolusanthus speciosus)? Our tree, two years old, has long “whips” with bunches of leaves on the ends, and we are not sure when is the best time to prune them and also encourage flowers – we had none this year, and thought it was because the tree was still too young.

    I look forward to hearing from you. Many thanks.

    Best regards
    (Mrs) Vanessa Lohmann

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