Tough and beautiful conebushes

Leucadendron laxum 'Jubilee Crown' Picture courtesy MadibriLeucadendron laxum 'Jubilee Crown' Picture courtesy MadibriAlthough conebushes are part of the Cape fynbos floral kingdom, as long as they are planted and cared for correctly they can thrive in many provinces in South Africa. Learn which species will thrive in your region, and how to grow them below.

Leucadendron salignum x laureolum 'Jester' Picture courtesy MadibriLeucadendron salignum x laureolum 'Jester' Picture courtesy MadibriLeucadendron is a genus of 83 species of flowering plants in the family Proteaceae, and a prominent part of the fynbos ecoregion. They are endemic to South Africa, and occur nowhere else in the world. Most of the species occur in the Western and Eastern Cape with a few outliers in KwaZulu-Natal.

They are all evergreen, and the flowers are produced in dense inflorescences at the tips of the branches of these dioecious shrubs or small trees, meaning that the male and female flowers are borne on separate plants. They are known as conebushes because the female flower heads form woody cones in which the fruits are borne. Most are small shrubs that grow up to 1m tall, while some reach 2 to 3m, and a few grow into moderate-sized trees up to 10m tall.

Like all members of the protea family, leucadendrons have adapted to growing in the nutrient-poor soils found in the mountains of the Cape by evolving proteoid roots which are dense clusters of hairy rootlets with a surface area 15 times that of non-proteoid roots, allowing the plants to absorb the tiny amounts of nutrients available in the soil. Proteoid roots are formed in a 50mm root mat around the plant in the soil just beneath the leaf litter, where nutrient supply is the highest. In nature they are formed only during the rainy season, but in cultivation where water is provided all year round they grow throughout the year. They also form more readily in soil that has added compost (humus or leaf mould). These roots are not formed in soil that has been fertilised with high levels of phosphates, making them difficult to cultivate in heavily fertilised soils.

The nutrients that are available are used up by the plants during their lifetime, and need to be returned to the soil in order to provide the food required for a new generation of plants to thrive. This is achieved by natural fires which sweep through the mountains every ten to thirty years. Natural fires occur mainly in late summer or autumn and are followed by the first winter rains, which provide the moisture the young seedlings need to grow to a large enough size to survive the following long, hot summer. The fire itself is believed to play a role in damaging the thick seed coat of the fruits, and the smoke it produces stimulates the germination process.

The seed heads of leucadendron are woody cone-like structures containing numerous seeds, giving rise to their generic common name conebush, and about half of the species store their seeds in these fire-proof cones, releasing them only after a fire has killed the plant. A few such as the Silvertree have silky-haired ‘parachutes’ attached to the fruits,  enabling the large round nuts to be dispersed by wind. The fruits of a few species are dispersed by rodents and cached by rats, and others have elaiosomes which ants love to eat, so they carry them underground where they are kept safe until conditions are perfect for germination.  

All are evergreen with largely elliptical, sometimes needle-like leaves which are spirally arranged along the stems. The leaves are usually green and often covered with a waxy bloom, and in the case of the silvertree, with a distinct silvery tone produced by dense, silky hairs. This inspired the generic name leucadendron, which literally means white tree.

Leucadendron argenteum. Picture courtesy MadibriLeucadendron argenteum. Picture courtesy MadibriLeucodendrons for the garden:

Over the years local and international plant breeders have developed an outstanding variety of hybrids and cultivars of conebushes, giving them special names. This is wonderful news but such a plethora of new names can become confusing for gardeners. Many of these will even flower at different times of the year, which is ideal for gardeners who plan to colour their garden throughout the seasons.

Because flowering times may vary slightly from year to year and region to region, bear this in mind when planning your garden. Also, there are just too many gorgeous varieties to list here, so do some of your own research to select the perfect ones for your garden and climate. Your local garden centre will stock those which are most suitable for your region - another good reason to visit an accredited garden centre for the best advice.

If you want to research the various species visit PlantZAfrica – my ‘go to’ website for information on indigenous plants. Click here to find their list.

Silver Tree, Witteboom (Leucadendron argenteum)

The silver tree is probably the most well-known of the conebushes with its beautiful silky, silver leaves. It is unique to the Cape Peninsula and grows in dense stands on cooler eastern and southerly mountain slopes, 100 to 150m above sea level, on granite derived clay soils which hold moisture yet are still free draining.

Over half of the wild tree populations occur on the slopes above Kirstenbosch, and there are eight populations spread over an 11km range, with good numbers at Wynberg Hill and Lion's Head, and a few outliers in Somerset West, Paarl and Stellenbosch. Only the populations at Rhodes Memorial and Tafelberg Road grow on shale derived soil.

Leucadendron argenteum is fast growing but relatively short lived, rarely living longer than 20 years. This lovely species is listed as endangered and could go extinct in the wild within the next 50 years if the remaining wild populations are not protected. Wild plants are attacked by a beetle, the silver tree borer, also known as the protea jewel beetle (Sphenoptera sinuosa), which bores tunnels in the roots and increases the chances of Phytopthora infection.

The silver tree is an erect, well proportioned, ornamental tree, growing 7 to 10m tall, with a stout trunk and thick, grey bark. The upright branches are covered with large lance shaped, silver-grey leaves which are covered on both surfaces with thousands of tiny, soft, silvery hairs, and fringed with long white hairs. The intensity of their silver sheen varies with the weather, and is most noticeable during hot, dry weather, when the hairs lie flat to protect the leaves from drying out. In wet weather they are not quite as dazzling because the hairs stand more erect to allow for free air circulation.

Flowering time is in spring (September to October) when the flowers appear in dense heads at the tips of the branches. The leaves that surround the flower heads, known as the involucral leaves, do not change colour while the tree is in bloom, but because they open wider and catch the light at a different angle, they appear to be brighter than the rest of the leaves. The male trees with their rounded buds are silver to pinkish silver, turning bright yellow and pink when open. Their flower heads are showier than those of the female trees, with their involucral leaves shining bright silver.

Leucadendron salignum x laureolum 'Inca Gold' Picture courtesy MadibriLeucadendron salignum x laureolum 'Inca Gold' Picture courtesy MadibriThe flower heads on the female trees are quite hard to find because they tend to be higher up on the tree and are not easy to spot from below, and the involucral leaves also conceal the heads. After pollination, the seeds take several months to develop, during which time the female cone enlarges to become egg-shaped, and densely covered in silver hairs.

The easiest way to tell a female from a male tree is to look for the previous year's cones on the older wood of the female plants. These remain silver and can be found below the current season's growth. The male flower heads dry to form small silver balls, falling off after flowering.

To survive fires, the silver tree has evolved a reseeding strategy by keeping its seeds safe in the large woody cones, and only releasing them in masse after a fire has swept through. A small percentage of the seeds are released in the absence of fire, enabling the population to produce a steady supply of young plants at all times. Despite the fact that the seeds are large, relatively heavy nuts, they are primarily dispersed by wind, because they are equipped with a plumed parachute-like appendage, which is the dried remains of the flower, enabling the wind to carry them a considerable distance from the parent plant.

The seeds are also eaten by rodents, which collect and store them in underground caches where many remain viable for many decades, and have been known to survive in the soil for up to 80 years. The alien grey squirrels also eat the seeds, taking them from the cones as they are opening.

Although the silver tree has a reputation for being difficult in cultivation, mainly because it is very susceptible to the root rot fungus Phytophthora, and like most members of the protea family dislikes soggy soils, still, humid air, and strong fertilisers, if cared for correctly, they are actually quite easy to grow and have been known to thrive far from their natural home. They are tender to all but very light frost and young plants should be protected in winter until they are established.

Silver trees are widely cultivated around the world as ornamental garden specimens, and their beautiful silver foliage is popular with florists because it lasts well in a vase. A single specimen is very striking, and because this is a small tree, it is a good choice for today's smaller gardens. For larger gardens or parks, a small grove of silver trees with their shimmering leaves makes a wonderful feature in the landscape. Because they are relatively short-lived, to maintain a small grove it is best to plant a number of young trees every few years.

Leucadendron argenteum is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Click here to find beautiful photographs and more information on growing and propagating the silver tree at PlantZAfrica

Leucadendron salignum 'Longtom' Picture courtesy MadibriLeucadendron salignum 'Longtom' Picture courtesy Madibri

Duinegeelbos, Geelbos, Dune Conebush (Leucadendron coniferum)

The dune conebush is an upright shrub with a single stem, growing up to four metres tall, and can be found from the Cape Peninsula in the west, through the coastal areas of the Kogelberg, Kleinmond and Groenland, to the Klein River Mountains in the east near Hermanus, where it grows in dense stands on wind-blown sands, from sea level to an altitude of about 300m.  

The long oblong-shaped leaves are slightly twisted with a sharp tip, and during their flowering season in spring (August and September), the involucral leaves that surround the flower heads turn a bright yellow. It is pollinated by small beetles, and the female cones turn red as they mature and later become green. The seeds remain in the cones for many years, or until a fire has swept through, after which they are released and transported by the wind.

This beautiful species is threatened by loss of habitat due to the invasion of alien trees, pollution, and in certain instances by unsustainable harvesting.

Leucadendron coniferum ‘Asteroid’ is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Flats Conebush, Silky Euryspermum, Tolbos (Leucadendron floridum)

This species occurs only on the low-lying Cape Flats, from Rondebosch to Kuils River and the Cape Peninsula. It is a wetland species which grows next to streams or in marshy places, where in winter its roots are often covered with water.

It is a tall, bushy shrub which can reach up to 2m in height, with slender branches and long, narrow leaves which are covered with silky hairs that produce a shimmering silver effect as the wind blows through the branches. During spring (September to October) the involucral leaves that surround the male and female flower heads turn a vivid yellow, and multiple flowers are produced on each stem, providing a very colourful display. It is pollinated by both beetles and wind, and both the male and female flowers are yellow. The females develop rounded silver cones that hold the very tiny seeds, and when they are fully ripe the cones open and the seeds are dropped to the ground, or are carried away by the wind.

Leucadendron salignum 'Madilime' Picture courtesy MadibriLeucadendron salignum 'Madilime' Picture courtesy Madibri

This lovely species is listed as Critically Endangered on the South African Red Data List. Wild populations have been drastically reduced because of habitat loss due to urban expansion, agriculture, and alien invasive plants. The only remaining two populations are also threatened by wild flower harvesting and incorrect fire regimes. In order to try to save this species, the plants have been propagated and planted at Kirstenbosch, with the view to reintroduce them into suitable habitats.

The flats conebush is suited to wetland areas or damp positions in the garden. The silver foliage will bring light and movement to your garden and it makes a good filler shrub or informal hedge. To add seasonal colour plant it in groups, together with other water-loving species like: Osmitopsis asteriscoides, Mimetes hirtus, Erica verticillata, Elegia nuda and Zantedeschia aethiopica.

This species requires a spot in full sun and if it cannot be planted next to a stream or vlei, it must be watered regularly. It grows quickly and is easy to grow in the garden, requiring minimal pruning. It can also be grown in a large container.

Click here to find beautiful photographs and more information on growing and propagating it at PlantZAfrica

Leucadendron floridum x coniferum has delightful yellow-green foliage and frost tolerant once established. It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Common Sunshine Conebush, Geelbos (Leucadendron salignum)

The common sunshine conebush is the most widespread species of the family Proteaceae, occurring in a large part of South Africa. It is common from Port Elizabeth in the east, to north of Ceres in the west, where it occurs on a wide range of soil types, from sea level to an altitude of 2 000m, and is also quite variable in leaf size as well as in the colour of the involucral leaves.

In the wild it is very variable in its growth habit and grows to heights between 75cm to 2m, and has a long flowering season (May to December). Its growing conditions also very from mild winter temperatures, to snow and frost near mountain tops. The colourful leaves surrounding the flowers vary in colour from greenish-yellow to a vivid orange-red, making this species an excellent candidate for breeding, as well as an attractive and popular garden plant. Its persistent rootstock enables it to re-sprout after fires.

There is a range of cultivars and hybrids between species in cultivation which differ markedly from the parent species, most often in growth form, leaf and bract colour, as well as flowering times. Many of these have been produced in South Africa, New Zealand, Australia and other countries.

The common sunshine conebush adapts well to vigorous pruning, which makes it suitable for the production of cut foliage on a large scale, making this species a natural choice for the wild flower industry.

Leucodendron salignum x laureolum ‘Safari Sunset’ This hybrid is one of the best known leucadendrons, and one of only a few hybrids grown at Kirstenbosch. It is a tall, erect and vigorous shrub growing up to 2.5m high and 1.5m wide, and is frost and drought tolerant once established. It is a valuable export flower crop in several countries because it produces its large deep-red bracts on long stems, flaring open to reveal lovely cream centres when in full bloom. Flowering can occur all year but its main flowering season is from autumn through to late spring. It is grow by Madibri – click here to visit their website and find retailers who stock this plant.

Leucadendron salignum x laureolum 'Safari Sunset' Picture courtesy MadibriLeucadendron salignum x laureolum 'Safari Sunset' Picture courtesy MadibriLeucadendron x laureolum 'Silvan Red' is a hybrid of the same two species but has a slightly lighter colour than ‘'Safari Sunset', and although usually hardy, is not as frost hardy as 'Safari Sunset'.

Leucadendron salignum ‘Blush’ flowers from September to November and has fiery orange-red foliage. It grows +-1.5m tall and 1m wide and is good in containers. It is frost and drought tolerant once established. It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Leucadendron salignum ‘Candles’ flowers from September to November and has wonderful orange-red foliage. It grows about 1m tall with an equal spread, and is good in containers. It is frost hardy and drought tolerant once established. It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Leucadendron salignum x discolor 'Disco Date’ grows about 1.5m tall with an equal spread. It flowers from September to November and has lovely creamy, orange-pink foliage. It is frost and drought tolerant once established. It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Leucadendron salignum x laureolum ‘Inca Gold’ flowers from September to November and has lovely green and yellow foliage flushed with red. It is frost hardy and drought tolerant once established, and grows about 1.5m tall with an equal spread. It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Leucadendron salignum x laureolum ‘Jester’ can produce flowers all year and has truly amazing variegated foliage in shades of green, yellow and crimson. It grows about 2m tall and 1.5m wide, and is an excellent container plant. It is frost and drought tolerant once established. It is grown by Madibri – click here visit their website and find retailers who stock this plant.

Leucadendron salignum ‘Longtom’ can produce flowers all year and has lovely long foliage in shades of purple and red. It grows about 2m tall and 1.5m wide and is frost and drought tolerant once established. It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Leucadendron salignum ‘Madilime’ can produce flowers all year and has lovely creamy-yellow and lime foliage. It grows about 1.5m tall with an equal spread, and is excellent in containers. It is frost and drought tolerant once established. It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Click here to find beautiful photographs and more information on growing and propagating the common sunshine conebush at PlantZAfrica

Leucadendron coniferum 'Asteroid' Picture courtesy MadibriLeucadendron coniferum 'Asteroid' Picture courtesy MadibriGalpin's Leucadendron, Hairless Conebush (Leucadendron galpinii)

Galpin's leucadendron is an upright evergreen shrub that grows in the Western Cape from De Hoop to Mossel Bay, occurring in low-lying areas between limestone hills, on deeper, neutral soils. It is found in Canca Limestone Fynbos, De Hoop Limestone Fynbos, Albertinia Sand Fynbos, Agulhas Sand Fynbos, Swellendam Silcrete Fynbos, and Hartenbos Strandveld.

It grows to about 2 to 3m tall and about 2m wide, and has lovely soft and narrow, silvery-grey foliage which is tinged with purple in winter and is borne on upright coral-red stems. It flowers in spring, and the male flowers are yellow pompons, while the female flowers are silvery-grey cones flushed with pink.  The seeds are wind-dispersed and released after fires. It is hardy to about -5°C and is a very useful and durable plant in the garden, adding a silver accent wherever it is planted.

This range-restricted species is threatened in the wild because it occurs in habitats that are targeted for destructive thatch harvesting, and management practises such as brush cutting aimed at encouraging dense restio growth.

Leucadendron galpinii 'Carlin' can bloom all year and has lovely blue-grey foliage and silver cones. It grows about 2m tall and 2m wide and tolerates frost and drought once established.
It is grown by Madibri – click here to visit their website and find retailers who stock this plant. 

Bredasdorp Conebush, Vleirosie (Leucadendron laxum)

The Bredasdorp conebush is a dense willowy shrub with small needle-like leaves, with a single stem at ground level and short branches clustered at the base of the plant. Both the male and female plants produce masses of small bright yellow flowers during spring and early summer (September to October), and are pollinated by insects. The flowers are followed by small rosy-pink to reddish cones on the female plants in summer, remaining decorative until the seeds ripen during autumn (March) of the following year. It is very unusual to find young seedlings in between the mature plants and regeneration normally only takes place after a fire. The attractive cones can be dried and used in dry flower arrangements or in Christmas wreaths.

It occurs in dense stands near the southernmost point of South Africa, where the Atlantic and Indian Oceans meet, where it can be found growing on damp coastal flats and in wetlands in the valleys between Hermanus, Bredasdorp and Agulhas. It occurs in Elim Ferricrete Fynbos, Agulhas Sand Fynbos, Overberg Dune Strandveld, Overberg Sandstone Fynbos, Agulhas Limestone Fynbos and Cape Lowland Freshwater Wetlands.

Leucadendron galpinii Carlin. Picture courtesy MadibriLeucadendron galpinii Carlin. Picture courtesy MadibriHow much longer the plants will be seen growing in the wild is uncertain, as it has lost half of its habitat due to the land being drained for farming. As a result its status in the Red List of South African Plants is Endangered.

In cultivation the Bredasdorp Conebush grows to between 1.5 and 1.75m high, and is a worthwhile addition to the garden, where it is shown to best advantage in dense plantings where it will provide pleasure with its bright yellow flowers and attractive cones. It prefers to be planted in a damp situation or otherwise it needs to be watered regularly. To add seasonal colour plant it in groups, together with other water-loving species like: Osmitopsis asteriscoides, Mimetes hirtus, Erica verticillata, Elegia nuda and Zantedeschia aethiopica.

It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Click here to find beautiful photographs and more information on growing and propagating Leucadendron laxum at PlantZAfrica

Golden Conebush, Laurel-leaf Conebush, Louriergeelbos, Louriertolbos (Leucadendron laureolum)

The golden conebush occurs on granite, sandstone and limestone slopes and flats, most often on deep sands, from sea level to 1 000m, from the Cape Peninsula eastwards to Potberg, north-east to Jonaskop and northwards to Paarl Mountain. Within this area it is found on the Cape Flats, Hottentots Holland Mountains, Kogelberg, Kleinmond, Groenland, Kleinrivier and Babylontoring Mountains, Elim Flats, Riviersonderend Mountains, Caledon Swartberg and Bredasdorp.

It is a large shrub with a single stem at the base of the plant, growing about 1 to 2m tall. The male bushes have a yellowish hue and are compact with a rounded shape, while the female bushes are greenish and less symmetrical, with fewer branches. Their oblong leaves are hairless when mature and end in a blunt, recurved, fine point.

During their flowering season in midwinter to early spring (June to August), both the male and female bushes turn a gorgeous bright yellow, and because they grow in dense stands, they paint the mountainsides yellow and are easily identifiable.  The male flower-heads have small yellow flowers, and the female flower-heads are made up of green scales with fewer flowers. 

They are pollinated by insects, and after flowering, the male flowers turn brown and drop off, but the female ones continue to grow, forming greenish yellow cones which are retained on the bush for several years, becoming hard and woody. The winged seeds are released after fires and are dispersed by wind.

Leucadendron laureolum. Picture courtesy MadibriLeucadendron laureolum. Picture courtesy MadibriAlthough this species is not widely cultivated for the cut flower market, it  is one of the parents of many commercial hybrids such as 'Asteroid', 'Chameleon', 'Red Gem', 'Silvan Red', 'Safari Sunset', 'Inca Gold', 'Magenta Sunset', 'Laurel Yellow', and 'Wilson's Wonder' to name but a few.

Leucadendron laureolum thrives in a wider range of soils than other leucadendrons which require acidic soil, and once established it is frost and drought tolerant. It is well suited to coastal and fynbos gardens, and excellent for gardens on sandy flats.

It is grown by Madibri – click here to visit their website and find retailers who stock this plant.

Click here to find beautiful photographs and more information on growing and propagating this species at PlantZAfrica

In the Garden:

Conebushes are ideally suited to low-maintenance gardens, and although most are excellent candidates for water-wise gardens, there are several species which love to grow close to water or in wetlands, making them extremely versatile in the garden, and  indispensable in Fynbos or Mediterranean style gardens. They are wonderful in wildlife gardens, and if you love flower arranging they are invaluable for cutting gardens.

Refer to the list above to find those most suitable for your soil and climate, and remember that your local garden centre will stock those most suited to your specific region.

Cultivation:

Although conebushes are part of the Cape fynbos floral kingdom, as long as they are planted and cared for correctly they can thrive in many provinces in South Africa, and around the world. Most do not thrive in humid regions, but a couple are more resilient to subtropical climates. Many like Leucodendron salignum also tolerate frost and snow, making them great for Highveld gardens, as long as they can be watered in winter. Most are drought tolerant once established, while others thrive close to water and in wetlands, and although most do not tolerate alkaline or heavy clay soils, some are more adaptable to average garden soils.

Leucadendron salignum 'Candles' Picture courtesy MadibriLeucadendron salignum 'Candles' Picture courtesy MadibriBefore deciding which conebushes you wish to plant, visit your local garden centre first for the best advice on which species or cultivars will do best in your region.

In the winter rainfall regions they are usually planted out just before the autumn rains arrive, but inland it is best to plant in spring or early summer when all danger of frost is over and just before the summer rains arrive. Young plants will need frost protection until they are established, and mulching the soil also protects the roots from cold. Keep the plants dry, during cold snaps, only watering moderately in between.

One of the most important factors to consider before planting is that most species require light and well-aerated soil with good drainage. If your soil is less than perfect, try growing them in containers or raised beds, and if your soil is not acidic, add generous quantities of a specialist protea soil mix to the planting beds.

If your soil is heavy but still drains quite well you can improve it to plant conebushes, but this must be done correctly. Simply filling a single planting hole with compost and planting is not the right thing to do, because the compost will form a reservoir for water to stand in, and this increases the chance of root rot. Instead, prepare an entire little bed for your plant, thoroughly digging in generous quantities of a specialist protea soil mix, and even some gypsum and washed river sand to break up clay.

Whether your soil is heavy or not, it is advisable to always prepare a small bed for planting rather than a single planting hole, after all your conebushes can live for a quite a long time, so it’s best to give them a good start. Once the bed is nicely dug over with its additives well mixed into the original soil, dig a planting hole at least twice the size of the container the plant came in, and transplant carefully so as not to damage the roots. Never plant deeper than the depth the plant was growing in its nursery bag or pot, and plant firmly in the ground, watering well afterwards. Water moderately but regularly for the first two years of growth, after which they should be well established and drought tolerant.

Leucadendron salignum 'Blush'  Picture courtesy MadibriLeucadendron salignum 'Blush' Picture courtesy MadibriConebushes also require full sun to grow and bloom well, but they also like to have a cool root system, so grouping them together, or combining them with other suitable fynbos plants will help shade the soil and roots. Planting a permanent groundcover around the plants when they are still young, which can be left to grow undisturbed, will also keep the roots cool, or you can just mulch the soil well.

Another important point to remember is that these plants love a lot of wind circulation around their leaves and cannot be grown in walled in areas with little or no air flow.

All proteas have what is called a “proteoid” root system, and plants with this root system form clusters of closely spaced short lateral rootlets which form a mat about 2 to 5cm thick just beneath the leaf litter. This type of root system allows the plants to grow in soil that isn’t rich in nutrients. For this reason they resent disturbance of any kind, so never cultivate around their roots. Weeds need to be pulled out gently by hand, and the plants must be sited in a part of the garden where they can be left undisturbed.

Water young plants immediately after planting and regularly thereafter to keep the soil damp but not soggy. When grown inland ensure that they are watered regularly from autumn to spring. Most garden soils are richer than the soils on which the plants grow in the wild and in these loamy type garden soils which retain moisture, watering can be reduced. However, young plants growing in sandy soil, or those being cultivated in pots, will need more frequent watering. Consider installing a drip irrigation system to water your protea collection. Watering at soil level is much better than overhead irrigation, as wet leaves are more susceptible to diseases.

Because our garden soils are generally quite fertile, it may not be necessary to feed plants growing in garden beds at all, and because fynbos plants are very sensitive to many fertilisers, never use chemical fertilisers, and especially those with a high phosphate or nitrogen content. Also, do not use bone meal, mushroom compost, or any kraal manures when planting.

Leucadendron floridum x coniferum. Picture courtesy MadibriLeucadendron floridum x coniferum. Picture courtesy Madibri

Young plants and those growing in pots will need feeding, and fynbos growers recommend that plants fed with organic fertilisers derived from fish emulsion or seaweed, diluted at half the normal recommended strength to help them along. For fully gown specimens in the garden they recommend feeding twice a year in spring and autumn with organic fertilisers like Seagro, Bio Ganic All Purpose, and Bio Ocean.

Apply organic mulches such as leaf litter, rough compost, or milled bark chips, around their roots. Never use manure. Pine bark, or pine needles are acidic and especially beneficial. These will break down slowly and feed the plant the natural way. Apply the mulch regularly, but do not make it too thick, and keep it well away from the stems of the plant.  Mulch will also help to suppress weed growth and keep the soil cool.

Pruning:

Pruning is not necessary unless the bush needs to be shaped, as this plant normally deadheads itself and the new branches then grow up from the position below the old flower head. However, because some conebushes can become fairly large shrubs, producing many spreading side branches which carry the blooms at their tips, to keep your plant neat and healthy you may need to do some basic pruning.

Regularly cutting for the vase is a way of pruning, but when cutting leave a piece of stem with healthy leaves, about 10 to 15cm long on the plant. Cuts where there are no leaves will simply cause die-back of the remaining portion of the branch.

Pruning to shape the plant is generally done after flowering to shorten branches, and remove any weak or unproductive stems from the middle of the plant to allow for more airflow and light to enter the centre of the plant. This will also help to prevent pest and disease infestation. Also remove any side growth growing downwards or lying on the soil.

Leucadendron Salignum x discolor 'Disco Date' Picture courtesy MadibriLeucadendron Salignum x discolor 'Disco Date' Picture courtesy Madibri

Propagation:

Conebushes can be propagated by seed or from cuttings. PlantZAfrica has detailed instructions on how to propagate the various species. Click here to find out more.

Problems, Pests & Diseases:

Like all Proteaceae, conebushes are quite hardy and do not suffer much from pests. The most harmful and destructive diseases are fungal. Most losses occur during the summer months when a virulent root fungus (Phytophthora camphora) can attack the plants. Control through the use of fungicides in the garden is difficult and expensive, and by the time the plant shows distress, it is normally too late to arrest the problem. The best methods of control are cultural, i.e. water plants early in the morning; keep soil surface cool by mulching; remove diseased plants immediately; do not over-water in summer; and prune and remove diseased material.

Click here for more detailed information on problems, pests and diseases affecting Proteas.