Whispering pine (Casuarina equisetifolia) is native to Asia, where it thrives mostly in coastal regions of the Indian and Pacific oceans.
In Kenya, naturally, it is one of the most popular trees in the Coast region, where it is widely used in the construction industry.
However, it is also grown in many hinterland regions across the country. It is known as mvinje in Kiswahili and omuyeye in Luhya.
The altitude in the ecological zones in which it grows is between 0 and 1,400 metres above sea level. The mean annual rainfalls range from 200mm to 3,500mm, according to Kenya Forestry Research Institute’s Guide to Tree Planting in Kenya.
Its seeds do not need any pre-sowing preparations. But because it is native to coastal regions with sandy soils, you have to mimic these conditions when preparing seedbeds. The seeds will germinate better, within seven to 14 days, if sowed in sand.
Alternatively, you may need to inoculate the seedbeds with soils from beneath mature trees. A kilo of seeds at Kefri Seed Centre at the Muguga headquarters costs Sh5,000.
Kefri also has seed sub-centres in Nyeri, Londiani, Kakamega, Kitale, Kibwezi, Gede and Turkana.
There are early dangers though that you have to look out for. In Soy, Uasin Gishu, where I have grown them since 2013, I once lost a substantial number of seedlings to worms.
The insects burrow in the bed and pot soil and emerge at night to eat through the stems of the seedlings. There is need, therefore, to spray with insecticide the moment you detect an attack.
This usually sorts out the cut worms. Apart from this, the growing tree is mostly free from disease attacks. It can grow up to a height of 30 metres, matures in about 20 years but can live up to 50 years.
Why plant this tree? Apart from its commercial value, it has a number of other benefits on the farm. Since it naturally grows in areas prone to tropical cyclones or typhoons, it has developed an extensive root system that is tolerant to strong winds.
This makes it one of the best wind breakers. It can also be planted near structures without any danger of being uprooted by strong winds.
The species conserves soil, improves fertility through supply of mulching material, green manure and nitrogen fixation in the soil. It helps in reclamation of degraded areas and sand-dune stabilisation on the coast.
Its needlelike leaves cover the ground in a thick carpet of brown, killing any undergrowth. But in dry seasons, they are a fire hazard.
Casuarina’s economic value is in firewood, charcoal, timber for roofing, furniture, poles (for house construction), fencing posts and making of boats.
Its popularity in the estimated $800 million furniture industry is due to the fact that its wood is soft and highly malleable. At an average of Sh50 a foot, it is also cheaper than cypress.
Its bark is a source of tannin, which is used in leather treatment, while root extracts are used in the treatment of dysentery, diarrhoea and stomach ache.
It is highly reputed as one of the best fuel species in the world. It burns readily even when green, and ashes retain heat for long periods.
Casuarina is processed into block boards and plywood for making furniture such as book shelves, tables and benches.
Other popular products are block board doors, flush doors and beds. Its fibre is used in the manufacture of paper.
Its extensive root system allows it to grow on barren, polluted sites. This makes it suitable for reclamation of degraded areas, according to Kenya Trees, Shrubs and Lianas, by Henk Beentje, published by the National Museums of Kenya.
Apart from the cut worms mentioned above, the whistling pine is rarely attacked by diseases and pests. However, this is not to say it is completely resistant to these attacks.
Infected trees exhibit symptoms of foliar wilt and cracking of the bark where blisters develop, enclosing a black, powdery mass of spores.
Bacterial wilt is characterised by yellowing of the foliage, followed by wilting and death. Pruning may make the tree susceptible to attacks by fungal pathogens. Insect pests include casuarina tussock moth, white-spotted longhorn beetle and cotton locusts.
For disease control, pruning should be avoided. Infected trees should be removed to prevent the spread of the disease and making trenches around groups of diseased trees to avoid root contact.
