Every October, Pretoria transforms into a sea of purple as tens of thousands of jacaranda trees burst into bloom. These flamboyant trees, native to South America but long naturalised in South Africa, line streets, parks and university campuses, creating an unforgettable spring spectacle. In this article we explore the history and significance of Pretoria’s jacarandas, offer tips on caring for ornamental trees and suggest indigenous alternatives for gardeners who want to celebrate our local flora.

The Jacaranda Phenomenon

Pretoria’s nickname, “Jacaranda City,” is well deserved. It is estimated that the city has around 70,000 jacaranda trees. In spring and early summer these trees are smothered with trumpet‑shaped purple flowers,

Historically, Pretoria’s jacarandas date back to the late nineteenth century. In 1888 a local nurseryman imported jacaranda seedlings and sold two to city councillor Japie Celliers. These “parent” trees were planted at Celliers’s home, and a plaque erected in 1939 records them as the city’s first jacarandas. When Pretoria received city status in 1906, nurseryman James D. Clark donated 200 jacaranda trees and school children planted them along many streets. A decade later the lawyer and horticulturist Frank Walter Jameson – nicknamed “Jacaranda Jim” – promoted mass plantings and established more than 40 miles of jacarandas. By 1939 the city had an estimated 17 000 trees and by the mid‑1950s roughly 25 000, turning Pretoria into a purple landmark each spring creating carpets of blossoms on the streets below. Jacaranda mimosifolia typically flowers for up to two months, beginning in October and continuing into November when temperatures rise. The blooms are not only beautiful – for many residents and students the falling flowers signal exam season and inspire local folklore about luck: catching a falling blossom is said to ensure success in your studies.

Although jacarandas are synonymous with Pretoria, they are not indigenous to South Africa. In Gauteng, KwaZulu‑Natal, Limpopo, Mpumalanga and the North West they are listed as Category 1b invasive species under the National Environmental Management: Biodiversity Act. This means they must be controlled and may not be planted or propagated except under specific exemptions – for example, large trees more than 400 mm in diameter in urban gardens or within 50 m of a homestead may remain. Water scarcity has also led authorities to discourage thirsty alien trees, so residents should not plant new jacaranda saplings. Existing mature specimens can be enjoyed and cared for, but gardeners seeking purple blossoms should choose indigenous alternatives that support biodiversity.

Caring for Established Ornamental and Indigenous Trees

Site selection and planting for indigenous trees and established specimens

If you already have an established ornamental tree in your garden, remember that many species (including jacarandas) grow very large and can reach 15–20 m with wide canopies. Ensure existing trees are well clear of buildings, pools and underground services. Indigenous flowering trees such as Cape chestnut, wild pear, tree wisteria and keurboom are usually smaller (about 4–10 m) and work well in suburban gardens. All of these trees prefer full sun and well‑drained soil. When planting any tree, dig a hole at least twice as wide as the root ball, mix in compost and a handful of KynoGarden® to enrich the soil, and water deeply after planting.

Once established, most ornamental and indigenous flowering trees are reasonably drought tolerant, but young trees need regular watering during the first few summers. Deep, infrequent watering encourages roots to grow downwards rather than staying near the surface. Feed your trees in spring with a balanced fertiliser formulated for shrubs, flowers and fruit – KynoShrub, Flower & Fruit® provides the right ratio of nitrogen, phosphorus and potassium for strong growth and abundant blooms. Apply according to package instructions and water in well.

Pruning and maintenance

Established ornamental and indigenous flowering trees generally require little pruning. Remove crossing or damaged branches in late winter before new growth starts, and lightly shape young trees to maintain a strong framework. Avoid heavy pruning as it encourages a flush of upright shoots at the expense of flowers. As with all trees, monitor for pests such as borer beetles and fungal diseases; early intervention with an appropriate treatment prevents serious damage.

Indigenous Alternatives

If you love the idea of a flowering street tree but want to plant indigenous, consider these South African beauties:

Cape chestnut (Calodendrum capense) – Indigenous tree producing masses of pink, star‑shaped flowers in late spring and early summer; grows 10‑15 m tall and thrives in sun and moderately fertile soil.

Wild pear (Dombeya rotundifolia) – Bears clusters of white, honey‑scented blooms in late winter and early spring; green leaves return quickly after flowering. This deciduous tree grows around 3–6 m tall and is frost and drought‑tolerant, making it a hardy choice for gardens.

Tree wisteria (Bolusanthus speciosus) – Deciduous tree bearing drooping mauve to purple racemes in late spring. It typically grows 6–10 m tall, tolerates drought and frost, and attracts butterflies an

Keurboom (Virgilia species) – Fast‑growing tree producing masses of pink to purple pea‑like flowers in spring and early summer. Depending on the species it grows about 4–10 m in full sun and well‑drained soil, and provides nectar for bees and bids..

Planting indigenous trees supports biodiversity, provides food and habitat for local wildlife and avoids the risks associated with invasive species. These trees also cope better with South Africa’s climatic extremes.

What to Look Out For

• Frost sensitivity – Young trees and other subtropical trees can be damaged by frost. In cooler regions like Gauteng’s Highveld, protect saplings with frost cloth during their first winter.
• Water stress – Prolonged droughts can stress ornamental trees. Mulch the root zone to conserve moisture and consider installing a drip irrigation system.
• Pests – Watch for signs of borers (sawdust, weeping sap) and powdery mildew on leaves. Early treatment with appropriate pesticides or fungicides is important.

Questions and Answers

Q: Can I still plant a jacaranda tree in Pretoria?
A: Existing jacaranda trees can remain, but planting new ones may be restricted depending on provincial regulations. Check with your local municipality or environmental agency. Consider indigenous alternatives for new plantings.

Q: How long do jacarandas bloom?
A: Jacaranda trees typically bloom in spring and early summer for up to two months. In Pretoria, the main flush of flowers occurs in October and November.

Q: What fertilizer should I use for my flowering trees?
A: Use a balanced fertilizer formulated for shrubs, flowers and fruit. KynoShrub, Flower & Fruit® is ideal as it provides essential nutrients and trace elements. Apply in early spring and again in midsummer.

Q: Are there indigenous trees with purple flowers?
Yes. Tree wisteria (Bolusanthus speciosus) produces clusters of purple flowers in late spring and is indigenous to South Africa. Cape chestnut (Calodendrum capense) produces masses of pink, star-shaped flowers; wild pear (Dombeya rotundifolia) offers clusters of white, honey-scented blooms; and keurboom (Virgilia species) produces pink or purple pea-like flowers in spring and early summer. These indigenous trees provide spectacular floral displays while supporting local biodiversity and are better choices for new plantings.