Welcome to Gardening in South Africa!

Acokanthera oppositifolia Picture courtesy Random Harvest NurseryDescription & Interesting Facts:

Bushman's Poison, Boesmansgif, inHlungunyemb, iNtlungunyembe  (Acokanthera oppositifolia) is an exceptionally attractive, medium to large tree or woody shrub (SA Tree No: 639). It grows wild in Limpopo, North West, Gauteng, Mpumalanga, KwaZulu-Natal, and in the Western and Eastern Cape.

The trees typically occur as part of the understorey vegetation in forests or at forest margins, but can be found in a variety of habitats, from rocky outcrops, coastal and riverine thickets, to open woodlands and grasslands

Bushman's poison It is one of three South African members of the genus Acokanthera, and belongs to the same family as many popular subtropical ornamental plants such as the Impala Lily (Adenium multiflorum)and Natal Plum or Num-num (Carissa macrocarpa),as well as exotics like Frangipani, Allamanda and Oleander.

This family is characterized by having very sweetly scented flowers and a sticky milky sap which is poisonous. The name Acokanthera is derived from the Greek and refers to the sharp anthers of the flowers. The species name oppositifolia refers to the opposite arrangement of the leaves.

Depending on climate and rainfall, bushman’s poison will grow moderately to a height of 2 to 7m with a spread of 1.5 to 2.5m. The main stem is typically short, with many upward growing branches and brown bark which becomes deeply grooved with age.  Young leaves are reddish-green, becoming a medium to dark, glossy green, with sharply-pointed tips and paler, often purple-red tinged undersides.

Butterflies are attracted to the dense clusters of white to pink-tinged, very sweetly-scented flowers which appear anytime from June to October, depending on the climate of your region. The large plum-coloured berry-like fruits are relished by birds.

Bushmans Poison. Picture courtesy Random Harvest NurseryUses:

All parts of the plant are highly poisonous with the possible exception of the ripe fruits. The milky sap was widely used by the Khoisan to form part of the cocktail used to poison the tips of their arrows for hunting.

Although the plants are highly toxic, traditionally, in its native regions it has various medicinal applications. It is used to treat snake and spider bites, intestinal worms, headaches, inflammations, colds, fever and even malaria.

In the Garden:

Although poisonous, bushman’s poison is safe to touch and is certainly a worthy garden subject.  It is also pest and disease-free, requiring minimal maintenance in the garden.  

The highly fragrant flowers can be smelled from a great distance away, and its non-aggressive root system makes it perfect for gardens large and small, and it even grows well in a pot.

If pruned regularly it makes an excellent hedging plant, and because it is wind resistant it’s also a great windbreak. For a hedge or windbreak plant 2 to 3m apart.

Bushman’s poison is easy to grow in shade to sun and is perfect for wetland and marsh gardens. And although it likes to be watered moderately, once established it is also remarkably water-wise, saving you a fortune on water bills.

Because the flowers attract a host of pollinators like bees and butterflies, and birds relish the fruits, bushman’s poison is invaluable in wildlife gardens.

Acokanthera oppositifolia Picture courtesy Random Harvest NurseryCultivation:

This species is widespread over many parts of the country with the exception of the drier parts, and those extremely cold areas.

Is bushman's poison hardy to frost and cold?

Bushman’s poison is quite hardy to frost and cold, with mature plants know to tolerate short spells when temperatures drop as low as -1°C. Young plants should be sheltered against extreme cold for at least the first 3 or 4 years.

In areas with severely cold winters pot culture is recommended, and it is advisable to move the container to a protected area during winter, and to protect the roots from the frost. Wrapping the pots with bubble wrap is a great insulator.

How much sun does bushman’s poison require?

The plant grows well in in sun, semi-shade or shade, but it does better with some shade, or half day, morning or afternoon sun.

What soil does bushman’s poison require?

Bushman’s poison is able to flourish in a wide range of soil types, from red clay to sandy or rocky soils, with a neutral pH, thriving in loamy or peaty soil. For good growth, add generous amounts of compost to the planting hole.

Does bushman’s poison need fertilising?

If planted in fertile soil the tree does not need feeding, but can be fed seasonally with a balanced organic fertiliser, together with mulch around the roots. Potted plants will respond well to regular feeding during spring and summer.

How much water does bushman’s poison need?

Although it grows best in areas with a mean annual rainfall of more than 600mm, mature plants are very water-wise and quite tolerant of drought. To keep the plant looking at its best in the garden, water moderately during long, hot and dry spells.  Water young plants regularly until they are established.

Propagation:

Propagation of this species is from seeds which are available online. Fresh seed collected from ripe fruit requires no pre-treatment, but has a very limited viability, and should be sown immediately after harvesting. Sow in a well-drained, river sand and compost mixture. Place in a warm, bright area, and keep the soil moist but do not let it become waterlogged.

 Semi-hardwood cuttings are taken from September to October from half-ripe, actively growing shoots.  They can be treated with a rooting hormone before being planted into a well-drained, river sand and compost mixture.

Caution:

All plants of the genus Acokanthera exude a milky latex which contains toxic cardiac glycosides strong enough to cause death. All parts of the plant are poisonous, with the possible exception of the ripe fruits.

Food prepared over fires kindled from the sticks of this tree, have proved fatal upon ingestion.

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Asparagus 'Meyerii' Picture courtesy Ball StraathofDescription & Interesting Facts:

Asparagus is the largest genus within the family Asparagaceae and consists of approximately 200 species, encompassing a large group of climbers and sub-shrubs which grow naturally throughout Africa, Asia and Europe. In southern Africa there are around 86 recognized species of Asparagus, which include herbaceous perennials, woody shrubs and climbers.

The South African Asparagus species are related to the European species and have a botanically very interesting structure. The so-called leaves are not true leaves at all, but are actually cladodes and are thought to be modified branches, while the spines are formed from modified branches or from modified leaves.

Most of our indigenous species have large, sharp spines. Asparagus densiflorus is the exception as its very small spines are hardly noticeable, making it an excellent choice for gardens. Asparagus ferns have a rhizomatous root system with long fibrous roots bearing oval, creamy-beige tubers. These tubers store nutrients and water, enabling the plants to survive long periods of drought, and to re-sprout if the stems are damaged in any way.

Asparagus densiflorus is an evergreen, scrambling and slightly woody perennial with upright or trailing branches up to 1m long, and because it can vary enormously in appearance, has resulted in many named cultivars or forms.

The best known forms belong to the commonly called ‘Emerald Ferns’ of the Asparagus densiflorus 'Sprengeri' group. These plants form large cushions of long arching stems, densely covered with dark green, needle-like leaves. The plants of this group can be used in large containers or hanging baskets, or as groundcovers in shade as well as in full sun,

The cultivars 'Cwebe' and 'Meyersii' are more upright plants; particularly 'Meyersii', which looks very different, with its dense, compact fronds, earning it the names ‘Cat's Tail’ or ‘Foxtail’.

Asparagus ferns are not only sought-after for their lush foliage but also for their very fragrant flowers which are tucked-in amongst the foliage, but are still endearing with their glossy, star shaped, white or pink flowers. Flowering times will vary according to climate, but is usually anytime from November to April.

Berries, 10mm in diameter, follow the flowers, starting off green and slowly ripening to a showy, bright orange-red, each one containing a single, hard black seed. Both flowers and berries can often be found on the plants at the same time.

The sweetly scented flowers attract butterflies and other insect pollinators, which in turn attract insectivorous birds and reptiles. The berries are relished by a wide variety of fruit-eating birds, such as weavers, white-eyes, thrushes, bulbuls, barbets and robin-chats, who disperse the seeds.

Cat's Tail Asparagus, Foxtail, Katstert (Asparagus densiflorus)

Asparagus densiflorus forms grows wild in the Eastern, Western, and Northern Cape provinces, KwaZulu-Natal, Gauteng, Limpopo and Mpumalanga. Its perennial nature allows it to grow in a wide range of habitats, from coastal dunes to rocky areas, bushveld and woodlands. It is specifically noted for its wild populations in coastal areas and forest reserves. It is also native to Eswatini (Swaziland) and Mozambique.

The cat’s tail is a soft textured, fast growing groundcover. It is drought resistant, takes light to moderate frost and is reported to be hardy to temperatures as low as -7°C, but under these extremes the plant will die back and become totally dormant until spring. 

The cat’s tail will adapt to sun or shade, thriving in semi-shaded areas of the garden, around a pond, in mixed borders, and in mass plantings as a groundcover. It’s also lovely cascading down from hanging baskets or over retaining walls, and in rockeries.

Asparagus densiflorus has many lovely cultivars, the most noteworthy of which are:

Cat’s Tail, Foxtail (Asparagus densiflorus ‘Meyersii’)

Meyersii is always in demand with South African gardeners for its ornamental value. It’s a neat, gracefully erect evergreen plant with dense, cylindrical branches which arch slightly at their tips.  The long stems emerge at a central point directly from the ground, and remain close together and often become woody and spiny at their bases as they mature. The plant can reach a height of 60 to 90cm, with a spread around 70 to 90cm. Myersii adapts to sun or shade, and withstands light to moderate winter frosts.

Grown primarily for its distinctive form and texture this asparagus remains one of the finest foliage plants. It thrives in outdoor pots, window boxes and hanging baskets and also makes an excellent indoor plant. Planted in mass it makes an effective ground cover with a matted root system that binds soil, preventing erosion. It is perfect for rock gardens, pebble gardens, and around water features.

Asparagus densiflorus ‘Cwebe’

Cwebe is a hardy, upright perennial with spreading fronds that cascade down gracefully. The exceptionally beautiful foliage is more fern-like than the other varieties, and new growth is a shiny, rich copper-bronze shade. Plant it in light shade, or underneath deciduous trees. It also makes a beautiful container plant for shady patios or light areas indoors.

 Asparagus densiflorus ‘Flagstaff’

Flagstaff forms long, arching branches that can grow up to a length of 1m and the plant can reach a height of up to 60cm.

 Asparagus densiflorus ‘Mazeppa’

As opposed to Flagstaff, Mazeppa grows into a thick and compact dark green mat, and does well on slopes or spilling over retaining walls, and is stunning in pots. It is fast growing, frost resistant, and does best in semi-shaded areas.

Asparagus densiflorus ‘Sprengeri'

This cultivar has long, gracefully arching stems with short needle-like leaves. It spreads or hangs down anything from 30 to 90cm, and does well in light shade, semi-shade or sun. Sprengeri is a beautiful plant for a dense border in garden beds which vary throughout the seasons from shady to sunny. It makes a good container plant, and its feathery foliage and arching habit is wonderful cascading down retaining walls or hanging baskets. It also grows well indoors.

Lace Fern, iphinganhloya, Climbing Asparagus, (Asparagus setaceus)

The climbing asparagus fern is found in savanna habitats in many of our provinces, including: Limpopo, North West, Gauteng, KwaZulu-Natal, Free State, Eastern and Western Cape.  It is a very hardy, drought-resistant climber with twining branches. The branchlets spread on one plane and have small, fine leaves in compressed clusters that look like lace.

The delicate foliage is extensively used in flower arrangements, and makes an unusual potted plant for indoors or outdoors.  In the garden it’s a good filler plant for shady to sunny areas, and over time it will scramble and cover nearby plants, reaching 3m in height under ideal conditions. Therefore, it may need to be controlled by pruning and removing runners once or twice a year.

Uses of asparagus ferns:

The asparagus lace fern is grown commercially for the cut flower industry as its gorgeous lacy foliage is a long lasting filler plant for flower arrangements.

The roots of some Asparagus species are used traditionally as vegetables, and many are used for medicinal purposes.

Asparagus Sprengerii Picture courtsy Ball StraathofCultivation:

Asparagus ferns are extremely hardy perennials that can be used outdoors in the garden and also as indoor potted plants.  They are easy plants for beginner gardeners, and do not require any special care.

Where do asparagus ferns grow best?

Asparagus ferns thrive in warm coastal and frost-free regions.

Will asparagus ferns take frost?

The plants will tolerate light to moderate frost, and some are reported to be hardy to temperatures as low as -7°C, but under these extremes the plant will die back and become totally dormant until spring.  Mulch the roots to prevent them from freezing or plant into pots which can be moved in winter.

Are asparagus ferns salt hardy?

Yes, asparagus ferns are known to be quite salt tolerant, but look at their best in coastal gardens if they are planted in a more sheltered position. Certain varieties like Asparagus densiflorus ‘Sprengeri’ grow naturally in habitats like coastal dunes and have excellent soil and salt spray tolerance.

How much sun do asparagus ferns need?

The plants looks at their best when grown in dappled sunlight or semi-shade, but can grow in full sun if they are watered regularly. Plants grown in full sun are more compact and dense than those grown in the shade. In too much shade the plants become lanky.

What soil type best suits asparagus ferns?

They are not fussy about soil but do really well in well-draining fertile soil rich in organic matter.

Fertilising asparagus ferns

Asparagus ferns are not very hungry plants in general, and if the soil is fertile in the garden, they will not require additional fertiliser. Potted plants can be fed twice a month during the growing season using a balanced liquid fertiliser diluted at half the recommended strength.  

How to water asparagus ferns

These water-wise plants should not be overwatered and do best if watered thoroughly, and are then allowed to almost dry out completely before watering again. The plant will quickly shed its foliage if overwatered.

Do asparagus ferns grow well indoors?

These ferns are popular indoor plants because they enjoy filtered light indoors with no direct sunlight. They will grow happily indoors in temperatures of 12 to 25°C. Try to avoid sudden drops in temperature and be wary of draughts.

A free-draining organic potting mix with added perlite will be ideal for this plant, allowing breathability for the roots.

They are grown in the same way as those outdoors, but indoors the plant will quickly shed its ‘leaves’ if over watered or placed in insufficient light. When you water do so thoroughly, then allow the soil to almost dry out completely before watering thoroughly again. Water sparingly in winter when the plant is not actively growing as the plant’s thick tuberous roots store water and sodden soil will cause the roots to rot.

Moderate humidity indoors together with regular misting of the foliage with water will be beneficial and promote healthy growth.

Indoors, the plants can be fed every two week or even monthly during their summer growth season using a liquid fertiliser diluted at half the recommended strength. It is unnecessary to feed during their winter rest period.

Asparagus 'Lace Fern' Picture by Forest and Kim Starr from flickrPruning asparagus ferns

Maintenance is minimal and you only need to remove any dead fronds or the occasional old, yellowed stem, cutting them off at the base of the plant.

To rejuvenate old plants, or those damaged by frost, cut them back completely right at the base of the plant, preferably in early spring before new growth begins. Afterwards a mulch of thick compost can be spread around the plant’s base to provide the food support needed for replenishing lost top growth. The plants will quickly produce healthy new green foliage after pruning.

Repotting asparagus ferns

These plants grow best when slightly root-bound, so only repot when necessary.

Repotting is usually done in early spring or summer but only increase pot size by a few centimetres. Shake off all the old soil around the roots before replanting in fresh potting soil.

Propagating asparagus ferns

Asparagus ferns can be propagated by division, ideally during active growth (but this is not essential). Separate the tuberous roots of crowded plants to plant into smaller pots in early spring or summer.

It is also often propagated from seed because it is so easy. Collect fully ripened fruit and remove the seeds from the flesh.  Sow in a growing medium for seedlings, keeping the trays in a warm and sheltered, semi-shaded spot, keeping the soil moist but not soggy.

The seeds will germinate in 4 to 6 weeks and the little seedling will grow slowly but steadily.  Fertilise with a liquid fertilizer at regular intervals, and once the seedlings are established, prick them out and repot into a compost-rich, loamy medium. Grow on in light shade, until roots are visible growing out the pots drainage holes. Your young plants are now ready to be planted out into the garden or pots.

Problems, Pests & Diseases:

Asparagus ferns are generally and naturally pest and disease free.

However, if grown indoors or outdoors under a roof in an enclosed patio, the plants may occasionally be affected by Aphids, Mealy Bugs, Scale Insects, and Red Spider Mites.

Incorrect care and lack of humidity, especially during warm and dry conditions are the main reasons pests may appear.

Keeping the humidity up by misting the plants down regularly with water, is a good pest deterrent. If you spot infestations early, simply taking the plant out into a shady part of the garden and hosing the foliage down with a strong stream of water can dislodge many or all of the pests. You can also trim the plant back completely and allow it to shoot again.

If pests persist treat with insecticidal soap or neem oil. Repeat weekly and keep the plant in isolation until it’s completely pest-free.

Effective Microorganisms (EM) has gained global popularity since the 1970's when Dr. Teruo Higa created it to enhance soil quality and plant growth. It is a mix of beneficial microbes that help in agriculture and waste management, using phototrophic bacteria, lactic acid bacteria, and yeast. It consists of over 80 microorganisms, and the coexistence of aerobic and anaerobic microorganisms and the exchange of food sources between them makes EM a uniquely life-promoting culture.

E.M. has undergone extensive testing and is proven to be safe for both humans and animals. It is a trusted biocontrol measure, controlling pests by releasing microorganisms into the soil. With EM, pests and pathogens are controlled or suppressed by means of natural processes, improving the soil quality for healthier plants, encouraging substantial growth from roots to foliage, flowers and fruit.

CLICK HERE TO FIND E.M. AND NEEM OIL AT OUR ONLINE SHOP

Why are the leaves of my asparagus fern turning yellow?

If your plant is being watered correctly and isn’t dropping leaves, but is yellowing, the possible causes are that temperature might be too high or the plant isn’t getting enough light.

Yellowing and dropping leaves usually indicates overwatering. Check how wet your soil is before you water, allowing the soil to dry out before watering again.

Why are the leaves of my asparagus fern looking scorched?

Scorched yellowing foliage with brown edges means your fern is getting too much direct light, move it to a cooler, more sheltered position. It can also be the result of leaving soil dry for too long. Asparagus ferns don’t like overwatering but potted specimens will require regular watering.

Indoors, dry air can also be a culprit, so increase humidity and remember that your plant won’t like being near a heat source, air conditioner or draught.

Why is the new growth on my asparagus fern small and weak-looking?

If the leaves are continuously small, your plant might not be getting enough light, so move it to a brighter spot. If it is already in a well-lit space, it may just need some feeding.  

Caution

Asparagus ferns are widely planted internationally, but sadly they have become invasive in several locations where they have been introduced in gardens.  Today Asparagus densiflorus and Asparagus setaceus are declared invasive weeds in Australia, and have the potential to become invasive in other countries with a similar microclimate to where they occur naturally in South Africa.

Toxicity

All parts of the asparagus fern are toxic to humans and other mammals. If ingested, the berries can cause low toxicity, resulting in vomiting, diarrhoea, and abdominal pain. If crushed, the berries may cause a minor skin irritation that luckily does not last for very long.

The toxic agent within the plant is sapogenin, a naturally occurring steroid.

Click here to read under Indoor Pot Plants

Calathea zebrina crop picture by K M from flickrDescription & Interesting Facts 

Calatheas are best known for their very diverse, colourful, and beautifully patterned leaves which look like they are hand-painted.  They are beloved indoor pot plants worldwide, but in tropical and subtropical regions they also flourish in gardens.

There are upwards of 50 different species of Calathea, and many of the most popular species also have many cultivated varieties - each one a living work of art!

Due to their intriguing and unique leaves people have given them several fun nicknames like: Peacock Plant, Zebra Plant and Prayer Plant.

Calathea illustris Picture courtesy Ball StraathofAs members of the Marantaceae family, Calathea is related to Maranta, and the two are often confused with one another. These two individual plants are often lumped together and commonly called "prayer plants". However, maranta is the true prayer plant as it closes its leaves up at night, and most Calathea varieties don’t close their leaves. You may however notice your Calathea moving its leaves throughout the day to direct itself towards the sunlight, something it’s evolved to do in its natural environment.

Many calathea species and their varieties have recently been reclassified into the genus Goeppertia, so you may now find them being sold under this name.

Calathea plants originate from the tropical rainforests of South and Central America, particularly the Amazon basin, where they grow in filtered shade under the canopy of trees. Their origins are rooted in this specific environment, which has given them unique care needs, such as a preference for low light and high humidity.

Rose Painted Prayer Plant (Calathea roseopicta 'illustris')

Illustris is a cultivar of the roseopicta variety that has become extremely popular among plant collectors. The tops of the ornately patterned foliage of this plant features pink and neon green accents to make it a true masterpiece.

Prayer Plant (Calathea roseopicta medallion)

Medallion is a cultivar with gorgeous dark purple and pink leaves with hints of green and deep burgundy undersides.

Caslathea Freddy (Calathea Louisae Freddy)

Freddy is a beautiful indoor plant, or outdoor understory plant for tropical and subtropical gardens. It is a remarkable specimen with very attractive patterned leaves which are slightly ruffled and striped with silvery-green patterning and deep purple undersides.

Round-leaved Calathea (Calathea orbifolia)

This calathea is the diva of the houseplant world and one of the larger species in the Calathea family. Under ideal growing conditions it can reach a height of 1m with a spread of 90cm. It also has large luxuriant leaves that are wider and more paddle-like, and the silver-green stripes make it a bold statement plant.

Pin Striped Calathea (Calathea ornata sanderiana)

You’re sure to fall in love with the unique leaf design of this calathea with its dark purple leaf and white-pink stripes, which look like they have been hand-painted.

Zebra Plant (Calathea zebrine)

Zebrina is popular and much loved for its striking bright green leaves with dark green zebra-like stripes.

Calathea orbifolia Picture courtesy Ball StraathofUsing Calatheas in the Home & Garden

In the moist and warm subtropical regions of South Africa calatheas can be grown outdoors in garden beds or pots.

In colder regions they remain popular indoor pot plants as their fancy foliage makes smaller specimens excellent picks for table-tops, and the taller growers are fantastic floor plants, or when placed on low plant stands.

Because calatheas are one of a very few colourful tropical plants that can be grown in low-light conditions indoors they remain extremely popular with homeowners and are perfect for the workplace.

Calatheas are also known to be air purifying plants, meaning they’ll take in carbon dioxide and other harmful air particles in their environment and release oxygen in return. If you keep a calathea in your bedroom, it might help you wake up feeling more refreshed than usual!

An added bonus is they are also pet and child friendly.

Cultivation:

Some people might find it a bit tricky to grow calathea well, but they are mostly rather easy providing they are given the right conditions.

The key to growing calatheas is to try to mimic their naturally humid and warm tropical environment as much as possible. With a little patience and care, your calathea will be a lush and long-lived member of your indoor plant collection.

Humidity:

Being natives of tropical rainforests, Calatheas thrive in high humidity and the leaves will quickly curl up or form dried-out patches in low humidity conditions.

In the drier regions of South Africa, to create a humid climate around your plant its best to place the pot in a larger drip tray filled with water and pebbles. The pebbles will ensure that the pot stands above the water, while allowing evaporation to take place, and thereby increasing humidity. Clustering several pot plants together will also help to increase humidity, as will the occasional misting down of the leaves with lukewarm water. Investing in a humidifier to place near your indoor plant collection will work wonders and is well worth investing in.

 Light:

Calatheas grow on the jungle floor where they received sun gently filtered through the tree canopy. Therefore they thrive indoors in lower light conditions than many other colourful tropical plants.  Give them warm, ambient light, as too much direct sunlight can bleach and burn their delicate leaves.

The same applies for specimens grown outdoors.

Soil:

These plants thrive in well-draining, slightly acidic soil. A mixture of potting soil, peat, and perlite works well. Fertilise every month during the summer growing season with a balanced, liquid fertiliser, but refrain from fertilising in the winter.

Calathea ornata sanderiana Picture courtesy Ball StraathofWatering:

The frequency of watering depends on the humidity and light conditions in your home. Calatheas prefer consistently moist but not soggy soil. If the roots stand in water for long periods, they might be susceptible to drowning or rot, so lift the plant in the drip tray using small pebbles.

Use lukewarm water to avoid shocking the plant, especially in winter, and allow the top few centimetres of the soil to dry out between watering’s. Investing in a water meter to use on your potted plants is well worth the outlay.

The plant is sensitive to fluoride and other chemicals in tap water, so filtered or rainwater is best.

Pruning:

Regular pruning is not necessary, but you can remove yellow or brown leaves to keep the plant looking at its best. Use clean, sharp scissors to prevent damage.

Repotting:

Repot calatheas every one to two years when they outgrow their pot, and spring is the best time to do it. To prevent overwatering choose a pot only slightly larger than the current one.

Propagation:

Propagation is typically done by division during repotting. Gently separate the plant into smaller sections, making sure each has roots, and repot them into separate pots.

Calathea louisae Freddy Picture courtesy Ball StraathofProblems, Pests & Diseases

Why is my calathea losing its colourful pattern?

Too much direct sun can "burn" leaves and dull the colouring. Calathea plants prefer warm, ambient light, so keep it in a bright room but move it away from the window.

Why do the leaves of my calathea have dry patches or edges?

Dry patches or edges usually occur when there is a combination of high temperatures with low humidity. They may also be caused by draughts and cold wind so keep the plant away these areas.

Outdoors select a place sheltered from strong winds.

Why are the leaves of my calathea curling?

Leaf curling usually indicates that the plant is not getting enough water or the humidity is too low. Ensure a consistent watering schedule and consider using a humidifier or setting the plant on a pebble tray containing a small amount of water.

Why does my calathea have black and brown patches on the leaves?

Black and brown patches on the leaves, especially young unfurling leaves, are signs of bacterial or fungal diseases like leaf spot. These could become a problem as the high humidity that these plants love is also the perfect breeding conditions for these ailments. Treat with a systemic fungicide and ensure adequate air movement to avoid stuffy conditions.

Regularly check your plant and treat any infestations or diseases promptly.

Common pests of caladiums

Common pests include spider mites, aphids, and mealybugs. Treat with a suitable insecticide.

Toxicity

In addition to their bright foliage, calatheas are also prized for their non-toxic nature, making them  a safe choice for households with animals and children.

Passiflora flower Image by Kathryn Bowman (nee Selfe) from PixabayDescription History & Interesting Facts:

Passiflora edulis is native to the subtropical and tropical regions of South America, specifically southern Brazil, Paraguay, and northern Argentina. It was introduced to other parts of the world by Portuguese and Spanish explorers and is now grown commercially in similar climates world-wide.

The fruit has been enjoyed by both humans and animals alike for thousands of years but was first documented in 1553 by Cieza de Leon, a civil servant in Colombia. He called the fruit "granadilla" (small pomegranates), and it is believed that the species he documented was potentially the Sweet Granadilla (Passiflora ligularis). Click here to see Google Images of this flamboyant vine.

In 1569, Nicolas Monardes, a physician in Spain, associated the passionflower morphology with the crucifixion of Christ, resulting in the flower being referred to by 16th century Spanish missionaries in Brazil as the “Flor de las cinco lagas” (Flower of the five wounds) and used to illustrate the passion and crucifixion of Christ to the native people.

The symbolism endured and in 1737 Carl Linnaeus established the scientific name of the genus as Passiflora, which means passionflower in Latin. This genus contains an impressive 550 species, each bearing the unique flowers it is known for.

Passiflora is classified as a “pepo” - a type of botanical berry, as are melons, pumpkins, and squash. Pepos are characterized by a hard rind, fleshy interior, and many seeds. Passiflora fits the bill with its round to oval fruits with their hard exterior and soft, juicy interior filled with numerous seeds.

Granadillas have an average lifespan of 3 years, but they can live longer if properly tended to.  Watch your older plant, and if it seems to decline or the fruiting decrease drastically, it probably needs to be replaced by a new one.

Giant Granadilla (Passiflora quadrangularis)

The Giant Granadilla is native to the tropical regions of South America. It is loved for its large, showy flowers and the greenish yellow fruits are the largest in the Passiflora genus. The 20 to 30cm oblong fruits are yellow-green with yellow to pink flesh, yellow seeds and a mild flavour.

Ripe fruits are eaten raw or made into drinks, and the immature green fruits are used as a vegetable in similar ways to how green papaya may be used, and the roots of old plants are baked or roasted.

Medicinally, the root and leaves are used as a soothing poultice for the treatment of liver problems. The fruit is used in the treatment of headaches, asthma, diarrhoea, dysentery, neurasthenia, and insomnia.

Giant granadilla plants are now available in South Africa, but please grow them responsibly in urban areas only, as, like the purple granadilla it could easily become invasive.

Purple Granadilla (Passiflora edulis)

The purple granadilla is a fast growing evergreen to semi-evergreen climbing vine with lovely glossy 3-lobed leaves and coiled tendrils which help it cling to supports. Depending on climate, the vine can grow anything from 3 to 15m in length, with an equal spread, though in home gardens it can be pruned to keep it smaller.

The white and purple flowers with their fringe-like corona of filaments that are white with a deep purple base, are as exotic looking as their name suggests, making the passionflower a favourite garden subject.  

The oval fruit measures 5 to 8cm, has a tough purple skin, orange flesh and black seeds. The purple granadilla is acidic but sweet, with a rich flavour and lots of juice, making it perfect for eating fresh.

Granadilla ‘Ester’

In South Africa the purple granadilla type, specifically the variety ‘Ester’ is the most commonly grown variety for commercial use and home gardens. Ester is a cross between the yellow (Passiflora edulis f flavicarpa) and the purple granadilla (Passiflora edulis f edulis). 

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Giant Granadilla Image by Maya A.P from PixabayPollination

Gardeners often ask why their granadillas don’t produce fruit, and the answer is simply a lack of pollinators in your garden and the type of granadilla you are growing.

Self-compatible granadilla vines produce fruit from their own pollen, requiring no other compatible tree. This is possible due to the flower morphology being structured so that the anthers are placed below the stigmas.

Self-incompatible fruits require pollen from a different yet compatible cultivar to set fruit.

Additionally, depending on the variety, the plants can be either self-compatible or self-incompatible.

Although Passiflora edulis is listed as being mostly self-incompatible, South African farmers and gardeners alike rely on honey bees and carpenter bees for pollination. Honey bees visit the flowers for both nectar and pollen, and the carpenter bee is the most efficient pollinator due to its foraging behaviour and larger size.

To assure the presence of carpenter bees, it is wise to have decaying logs on the ground among the vines to provide nesting places. Attracting bees is easy if you provide them with food sources in the garden.

The pollen of passion fruit flowers is heavy and sticky, making wind pollination ineffective. Hand pollination may be necessary if there are not sufficient natural pollinators in your area.

In addition, the amount of pollen deposited on the stigma during pollination determines the number of seeds set and size of the fruit. A passionfruit can develop hundreds of seeds and if too few of the ovules develop into seeds the fruit is likely to be hollow and light in weight with little juice.

Health benefits of granadillas

Granadillas are a source of proteins, minerals, vitamins, carbohydrates and fat.

They are loaded with vitamin C, a great antioxidant our body uses it to make blood vessels, cartilage, muscles, and collagen which keeps your skin looking young. It also helps your body heal, lowers inflammation, and protects your cells from damage. They are also a good source of vitamin A, essential for healthy eyes.

When eaten whole, the seeds have a fibre content of approximately 1.9 grams, making the fruit good for gut health and preventing constipation. The seeds also are a good source of protein, minerals, and heart-healthy fats. Some research suggests compounds in the seeds may also help relax and widen blood vessels, adding to their cardiovascular benefits.

Passion fruit also gives your body calcium, magnesium, phosphorus, potassium, and folate. These help boost the health of your kidneys, nerves, muscles, and heart.

Eating granadilla regularly helps the body produce red blood cells, white blood cells and platelets. Thanks to the iron, potassium, phosphorus and vitamin B the fruit contains, the production of these blood cells increases, helping to prevent conditions such as anaemia.

Passionfruit Tart Picture courtesy PixabayIn the Kitchen

If you’re a fan of both sweet and sour flavours you’re sure to love granadillas, so transport yourself to the tropics with tangy passionfruit - there are so many possibilities when it comes to this fruit.

It adds a tangy twist to both sweet and savoury dishes, so mix up a fruity passionfruit cocktail - try a Maracuya Sour or Passionfruit Mojito. Indulge in a summery passionfruit parfait, or a dark chocolate and passionfruit ganache. Mix it into vanilla buttercream frosting for icing cakes and cupcakes. Add it liberally to tarts, and for special occasions make a passionfruit Pavlova.

Make passionfruit jam with 1 cup pulp, 1 cup sugar, 1 tsp pectin, and 1/4 tsp vanilla. Enjoy it on toast, mixed into yogurt, or as a cake filling.

Try pairing passionfruit sauce with fish, duck, turkey or chicken, or turn it into a salad dressing, using the pulp and the seeds which add a lovely crunch, combined with vinaigrette made with lime juice and extra virgin olive oil, sugar, salt and black pepper.

Cultivation:

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What climate is best for growing granadillas?

Granadillas are native to warm tropical and subtropical regions and thrive in relatively high humidity, and where rainfall is good, at least 1 200mm per year.

They do best in moderate temperatures with a minimum of 5°C and a maximum of around 30°C.

Is granadilla frost hardy?

Granadillas are sensitive to cold and frost, and cold soil temperatures may cause inter-vein yellowing of the leaves. In moderately cold climates they can be planted outdoors in a warm spot where they are sheltered from cold winds. A sunny wall or warm patio would provide protection.

In cold regions, you will need to plant into containers that can be brought indoors, or moved to a more sheltered outdoor location near a north-facing wall or under a covered patio for winter protection. A covering of frost protection cloth works wonders in protecting sensitive plants, and wrapping the pots with bubble wrap will help keep the soil warm in winter.

During cold winters granadillas could go dormant, but if they are protected should, bounce back and shoot again in spring.  

How much sun do granadillas require?

Granadillas need lots of sun to grow strongly and produce the best fruits. They will still thrive in lightly shaded areas. In hot and drier climates, they will benefit from light afternoon shade to prevent scorching, or full morning sun.

How much water do granadillas require?

Granadillas like to be kept moist, but absolutely hate being waterlogged, so good drainage is vital. Thorough and deep watering is particularly essential while the fruits are maturing.  If the soil is allowed to dry out during this stage, the fruit might shrivel up or fall from the plant.

Regular watering will keep a granadilla vine flowering and fruiting almost continuously – up to three harvests a year. Irrigation - up to 15 litres per plant per day can supplement low rainfall.

Planting granadillas

In warm regions granadilla plants can be planted at any time, but in cold regions early spring, once all danger of cold weather is over is best. Prepare the soil in advance by digging a hole of 1m x 1m and enriching the soil as detailed below.

When planting your vine, plant it no deeper than it was in the bag or pot you bought it in, and plant trellises at the same time to avoid damaging the roots later.

If you’re planting more than one vine, space the planting holes 1.5m apart.

What soil is best for granadillas?

Granadillas prefer a slightly acidic to neutral pH, ideally between 5.5 and 7.0, though some sources recommend a narrower range of 6.5 to 7.5 for optimal fruit production.  

As granadillas have deep root systems, the soil should be rich in organic matter to ensure it is loose and well-draining. Avoid compacted or clay soils that have not been amended. Improve poor or sandy soil with lots of compost and mix some bonemeal, superphosphate or organic 2:3:2 into the soil at the bottom of the planting hole to encourage good growth.

Alternatively, consider adding Superfrass and Volcanic Rock Dust to your composted soil for fantastic results.

Superfrass is a natural high quality organic growth enhancer and pesticide. It is packed with macro-elements (N, P, K) and micro-nutrients (Zn, Cu, etc.), which enable your plants to grow robustly. It also contains Chitin, a natural molecule that helps plants to defend themselves against insects, disease pathogens and predators, such as root feeding nematodes.

Volcanic Rock Dust contains more than 72 minerals and trace elements that nourish the soil returning it to a healthy, rich state. Obviously, healthy soil will produce healthy plants. It is very easy to use and will never ‘burn’ a flower or plant, and a little will go a long way!

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Fertilising granadillas

Granadillas are fast, vigorous growers and need a lot of nutrients.

At the beginning of the growing season, in July/August, feed the plants with a balanced organic fertiliser like 2:3:2.

In December apply an organic fruit fertiliser like 3:1:5, and repeat again in April.

If you notice any deficiencies in your plants, apply any liquid fertiliser containing micro-nutrients. This can be done once a month during the active growing season to prevent deficiencies.

Growing granadillas in pots

Granadillas thrive in large, sturdy pots which can support a trellis. This also helps keep the vines contained and great for smaller gardens with little space for outdoor planting.

Plant in rich well drained soil and treat as for vines growing in the ground. However, you will have to check for watering more often and potted vines will also need regular feeding. Liquid or slow release fertilisers are ideal for potted plants and convenient to use.

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Staking granadilla vines

Granadilla vines are very strong and vigorous growers and require a sturdy support in the form of a trellis, fence, wall, arch or gazebo to grow up against. This also allows for easy pruning and harvesting.

Granadillas can also be trained to grow along a wall (espalier) which is very practical and space saving for urban gardens.

Initially you might have to tie the main stem to the support with a soft tie, but the little tendrils on the shoots will quickly start attaching themselves.

Don’t let them grow against or up other plants or trees as they will very quickly get out of hand and take over.

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Companion planting to encourage pollinators

Planting a variety of flowers and flowering herbs near your granadilla will attract pollinating insects– this is vital for quality fruit formation.

Pruning granadillas

Granadillas only set fruit on new growth so pruning is essential. Pruning is best done before the spring flush of growth. Remove all tangled branches and deadwood. Then cut all the healthy shoots back by about one third to promote new, strong growth and abundant fruit.

Harvesting & Storing Granadillas

It may take around two seasons of growth before your plant starts producing fruit, after which two main crops can be harvested per year in South Africa. A summer crop is harvested from November to January, and another smaller crop can be picked in winter (June to July). Some granadilla producers in the Northern and Mpumalanga provinces may have a third small harvest in March/April. Purple granadillas ripen earlier than the yellow type.

Granadillas are climacteric fruit i.e. they will continue to ripen after harvesting. Ripe granadillas become sweeter after harvesting, but green granadillas will not ripen fully off the vine. Ripen at room temperature or store in a refrigerator when fully ripe.

Purple passionfruits are picked for the fresh fruit market when the skins are light purple. When used for processing such as juicing, the fruit is picked when skins are dark purple. Commercial growers may apply a wax to the skins to prevent shrivelling and drying.

Gardeners generally pick the fruits when they are fully developed and dark purple in colour, and the fruit falls from the plant if you shake it gently. Fruits wrinkle as they mature and this is when they are at their best! Harvest early in the morning before the heat of the day.

Propagation

Granadillas can be grown from cuttings or seed. To grow from seed, allow fruit pulp (with seeds) to ferment for a few days in a plastic container. Wash to separate seeds from the pulp and sow in well-drained soils.

Granadilla Image by andreas N from PixabayIs Passiflora edulis invasive in South Africa?

Passiflora edulis has naturalised and become invasive in many countries, including New Zealand and South Africa.

Passiflora edulis is one of 14 species of Passiflora introduced to Southern Africa, eight of which became naturalized, and four which were declared Category 1 invasive plants. Category 1 invasive plants are restricted or prohibited and must be removed and destroyed, as they have high invasive potential, smothering indigenous trees and shrubs.

While not as serious an invader as some other species, Passiflora edulis is nevertheless listed as a Category 2 invasive in parts of South Africa.

Category 2 invasive species are regulated by area. A demarcation permit is required to import, possess, grow, breed, move, sell, buy, or accept as a gift any plants listed as Category 2 plants.

Special exemptions are given for commercial growers. No permits will be issued for Category 2 plants to exist in riparian zones – the transitional areas where terrestrial land meets water bodies like rivers, lakes, and streams.

Legislation is often confusing and is continually changing, but currently Passiflora edulis is classified as a Category 2 invasive in the Eastern Cape, Gauteng, KwaZulu-Natal, Mpumalanga, Limpopo and North-West.

However, cultivation may not be restricted in urban areas of the above listed provinces, so check before purchasing plants.

Passiflora edulis is not listed as invasive elsewhere in South Africa.

Problems, Pests & Diseases of Granadillas

Granadillas may show signs of zinc and boron deficiency

Zinc deficiency in granadillas can be managed by using foliar sprays containing zinc, especially in spring, and ensuring the soil has proper drainage and nutrient balance. Symptoms include small, distorted leaves and yellowing between the leaf veins, often appearing on the youngest shoots.

Boron deficiency in granadillas can cause misshapen, bumpy, and malformed fruit, along with stunted growth and poor fruit set. Other symptoms include deformed young leaves and, in severe cases, a risk of the growing point dying. Climatic conditions where there is a severe reduction in water supply (droughts) are typically the initial condition for the occurrence of this deficiency.

Both Boron and Zinc deficiencies can be treated using Trelmix, a trace element solution used to correct deficiencies and promote overall plant health by supplying essential micronutrients, vitamins, and minerals. It enhances root and foliage development, boosts resistance to disease, and helps correct issues like yellowing leaves (chlorosis). Trelmix is applied as a soil drench or foliar spray and can be used alongside regular fertilisers.

The main pests and diseases of granadillas are Fusarium wilt, nematodes and crown rot. Nematode damage is visible as stem lesions near the soil line. Footrot is caused by waterlogged soil.

The yellow granadilla is more resistant to wilt and nematodes and is used as a rootstock for the purple variety.

Both variants are susceptible to Phytophthora cinnamoni.

Snails attack granadilla leaves and thrips can be a problem on seedlings.

Caution:

Passion fruit poisoning

The pulp contains a substance called cyanogenic glycoside -- a common natural toxin also found in cassava, apple seeds, apricot pits, almonds, and other plant foods. This chemical can cause cyanide poisoning in very high amounts. It’s highest in very young, unripe passion fruits. Once the fruit is ripe, it’s safe to eat.

Passion fruit allergy

Some people are allergic to the fruit. This is more likely if you’re allergic to latex.