Pentas shine even in the hottest of summers!

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Pentas 'Lucky Star' Picture courtesy Nu-leaf NurseryPentas 'Lucky Star' Picture courtesy Nu-leaf NurseryLow-maintenance and water-wise Pentas enjoy the summer heat and continually produce their pretty, star shaped flowers right through the summer months, or almost all year round in the subtropical or frost-free regions of South Africa. Read more below on growing them in pots and garden beds.

Pentas is also commonly called “Star Flower”, "Star Cluster" and "Egyptian Stars" for its large clusters of small, star-shaped flowers which are copiously produced throughout the warmer months, or almost all year round in the subtropical and other frost-free regions of South Africa.  In cold winter regions they are popular summer bedding plants. Overall, pentas are pretty low-maintenance, water-wise,  and easy to grow in any garden setting, and the reason why they are grown so extensively throughout both the tropical and temperate regions of the world.

Pentas lanceolata is a species of flowering plant in the madder family, Rubiaceae, and is native to much of eastern Africa, including Madagascar, and the Arabian Peninsula, as well as Yemen.  Older garden varieties of pentas were quite beautiful but they could become a bit scraggly if not regularly pruned, so plant breeders started working on developing newer varieties, and today there are exciting ones which are more compact, very floriferous, and come in lovely shades of pink to red, purple to lavender, and white. The blooms show up beautifully against the pretty green leaves, and butterflies seem to be drawn magnetically to the flowers. Newer varieties are also bred with improved disease resistance.

In warmer sub-tropical regions which receive good summer rainfall, pentas plants will grow more vigorously and will attain greater heights than those grown as summer annuals in the cold winter regions. For this reason the height and spread shown on plant labels is only approximate.

These new generation of hybrids are squat, compact plants, varying in height from 30 to 60cm, and if the plants are trimmed lightly after each flush of flowers, they will continue to bloom throughout the warm months.

Pentas 'Lucky Star' is a delightful mixture of pink, red, rose, violet, and white flowers and grows to a height of +-30cm, and spreads 20cm. It loves full sun and is perfect for borders and containers.

Pentas 'Northern Lights' is a new variety of Pentas with masses of pale lavender, star-shaped flowers which are produced in large umbels continuously throughout the season. This larger growing pentas grows +-50 to 60cm tall, with a 30cm spread, and makes an excellent background plant in flower borders and in large containers. It grows best where it receives full morning sun and some late afternoon shade, otherwise it is unfussy.

Pentas varieties in single colours are also available, and are given various names, so enquire at your local garden centre about pentas.

Uses:

Pentas is commonly used as herbal medicine in Ethiopia, Uganda, Rwanda, and Kenya. In these regions Pentas lanceolata leaves and roots are used topically and orally to treat lymphadenitis, diarrhoea, and even snakebite. Malaria vaccines are not cheap or easily available to rural Africa, so instead, they use traditional medicine to treat malaria and one of the plants used is pentas.

Ascariasis, a disease caused by Ascaris lumbricoides, a parasitic roundworm that grows inside the body causing enlargement of the liver and inflammation of the lungs, is not a common ailment in most parts of the world, but in rural parts of Africa, this is a frequent problem. The Conventional treatment to heal this ailment is to kill the roundworm with Ascaricides, which is taken orally. In the traditional treatment of Ascariasis, the root of Pentas lanceolata is boiled and the mixture is taken orally.

Ascariasis is also a common livestock disease, and rural African people give their cows pentas leaves, not the roots, to chew on as a treatment for Ascariasis.

A study done by scientists from the Department of Botany, Scott Christian College, and Nesamony Memorial Christian College in India, showed the presence of phytochemicals such as alkaloids, flavonoids, carbohydrates, phenols, terpenoids, coumarins, phytosterols, and quinones in Pentas lanceolata.

Pentas 'Northern Lights' Picture courtesy Nu-leaf NurseryPentas 'Northern Lights' Picture courtesy Nu-leaf NurseryIn the Garden:

If you have a hot, baked spot in your garden, pentas is the answer! Their low maintenance requirements, lovely foliage and bright flowers make pentas a welcome garden addition. They look good anywhere- in the mixed border they look wonderful in front of dark green shrubs, and also make an excellent backdrop for shorter growing summer flowering annuals and perennials. Pentas are also used to great effect in pots and hanging baskets when combined with other small summer bloomers.

The five petals of star-flowers represent faith, hope, charity, justice and peace, and because they last very well in a vase, are perfect for small bouquets.

The flowers attract butterflies like a magnet, drawing them in by the dozens, and they are also very attractive to bees, sunbirds, and many other pollinators.

Pentas can be used to dramatic effect in landscaped flowerbeds when planted in groups, or in large drifts of uniform colours, interspersed with drifts of any number of other warm weather summer plants. 

Group pentas together with other water-wise, sun loving plants like:

Members can click on the highlighted text to read more about the plants mentioned.

Lantana montevidensis also attracts butterflies and produces an abundance of brightly coloured flowers all summer and autumn.

The annual Red Salvia is a good companion, as are the many perennial species of salvia, especially the blue flowered ones, which look fantastic with pentas.  

Marigolds are well known for their hardiness, heat and drought tolerance, and with the wide range available, form tiny dwarfs, to giant doubles, in shades of yellow, orange, or cream, they are well worth investing in to pair with pentas.

Vinca, Madagascar Periwinkle, is not called “Kanniedood”  in Afrikaans for nothing – it is truly one of the most reliable and water-wise plants to grow in the blazing sun.

Pentas also goes well with other popular and well-known summer annuals like alyssum, petunias and verbena, to name but a few.

Cultivation/Propagation:

In the subtropical, humid, and frost-free regions of South Africa pentas is grown as a short-lived perennial plant, and can be planted at any time of the year. In regions like the Lowveld and even in Cape Town it is known to bloom almost all year round.

In cold winter regions pentas is treated as a summer annual, and is best planted out in late spring once all danger of late frosts are over, and the temperatures are nice and warm. Because pentas can survive a light frost, but cannot survive a hard freeze, gardeners sometimes plant them into pots which can be covered and moved to a warm, sheltered spot to overwinter, but it is sometimes less hassle to simply buy them fresh each season.

Pentas are known to thrive in full sun, or where they receive at least 6 hours of bright sunlight a day, and in too much shade they can become lanky and will not flower well. However, certain varieties like Pentas 'Northern Lights' will thrive in full morning sun with some afternoon shade. In very arid and hot regions the plants will certainly appreciate some shade during the hottest time of the day, and will also require regular watering.

Pentas prefers a well-drained soil that doesn’t stay soggy after heavy rainfall or irrigation. It also likes a fertile soil, so work in generous amounts of compost or other organic matter into the planting beds, and for potted specimens, a good, well-drained potting soil will work well.

Pentas is considered to be moderately drought tolerant, and therefore a water-wise garden plant, but if you want your plants to perform well all summer, if there are long, hot spells with little or no rainfall, moderate but regular watering will keep them blooming. Keep an eye on potted plants as these will dry out quicker than those growing in garden beds.

Fertilise monthly using any balanced plant food for flowering plants, and for potted specimens, using a water-soluble plant food may be more convenient. Alternatively, for the busy gardener, the addition of a granular slow-release fertiliser to beds or pots will slowly feed your plants all season long.

The importance of deadheading cannot be over emphasised as this enhances their garden performance enormously, and encourages re-blooming. Selective pruning throughout the growing season will also keep them in shape, so feel free to snip out dead or overgrown stems during the growing season.

If you are growing pentas as perennials, and the plants get too long and woody, do not be scared to cut them back by at least half – the plants will quickly rejuvenate themselves. To encourage low branching and bushy growth, pinch the tips out when the plants are young, or when a new growth flush emerges.

Propagation:

Softwood cuttings taken in spring and summer will root very easily. Seed can be also be sown in spring, but because the seeds do not store well, ensure that they are fresh, and sow them as soon as possible.

Homeowners will find growing from cuttings the easiest. Prepare small pots or seedling trays with any moistened starter medium. Equal quantities of peat moss and perlite mixed together works well for cuttings. Take woody tip cuttings about 10cm long, trim off the bottom leaves, and dip the end in a rooting hormone solution or powder.  Make a hole in the soil and plant the cutting deeply, or up to the leaves, firming the soil down well. Water and place the cuttings in a shaded location out of direct sun and the wind. Keep the soil moist but not soggy, and the cuttings should begin to root in only a couple of weeks.

Problems, Pests & Diseases:

If grown correctly pentas don’t suffer from any serious pests or diseases.

Since this plant is a delight to butterflies, their caterpillars can feed on pentas leaves, so if you do find some caterpillars, please allow them to feed and transform into the beautiful butterfly they were intended to be.

Pentas will not thrive in very acidic soils.   

Saturated soil can lead to rotten roots, and fungal diseases.

A fungicide spray containing copper will help control botrytis, mildew and leaf spots. Limit the spread of the plant disease by removing the affected leaves.

Watch out for common garden pests like aphids or spider mites, fungus gnats, and whiteflies; and treat them with an insecticidal soap spray, or organic all-natural neem oil insecticide like: Biogrow ‘Bioneem’.

Bioneem is used to control a wide range of insects (up to 200 insect types) including white flies, leafminers, mealybug, thrips, fruit flies, leaf hopper, red spider mite, weevils and many more.

Azadirachtin is relatively harmless to insects that pollinate crops and trees, such as butterflies, spiders and bees; ladybugs that consume aphids; and wasps that act as a parasite on various crop pests. This is because neem products must be ingested to be effective. Thus, insects that feed on plant tissue succumb, while those that feed on nectar or other insects rarely contact significant concentrations of neem products.

Warning:

Pentas flowers are non-toxic to dogs, cats, and human, but always supervise small children in the garden and discourage pets from chewing on plants.

In this website we document the uses of plants as recorded in history, but we do not advocate the use of any of these plants to cure anything. Always consult with a physician before using herbal remedies.