The art of farming healthy roses: Eleven things you need to know

The horticultural sector is Kenya’s third-largest foreign exchange earner. The flower industry directly employs 150,000 people and contributes 1 per cent of the country’s Gross Domestic Product.

The main cut flowers grown in Kenya are roses, carnations and Alstromeria.

Roses varieties in Kenya include Red one, Fusciana, Inka, Moon walk, Sweet unique, Athena, Star fish, Queen Africa, Top sun, Avanti, Amani, Tropical amazon, Oracle, Super Akito among others.

Kennedy Mbugua, a florist and a farmer in Kiambu County says flowers play a key role in the growth and development of the country’s economy as well as creating employment.

The main production areas of roses and other cut flowers are around Lake Naivasha, Mt Kenya, Nairobi, Thika, Kiambu, Athi River, Kitale, Nakuru, Kericho, Nyandarua, Trans Nzoia, Uasin Gishu and Eastern Kenya. For those interested in starting a flower farm, this is what you need to know: 

Ecological conditions

The crop does well in sunlight, humid and moderate temperatures of between 15 degrees to 28 degrees celcius is ideal for rose cultivation.

The soil should be well-drained and rich in organic matter and oxygen and pH of six to 6.5. Farmyard manure can be added to make the soil rich.

“Soil loosening on beds should be done after four to six months for efficient irrigation,” says Mbugua.

Planting and propagation

Rose plants are mainly propagated by seed, layers, budding and cuttings. Budding is one of the best methods for propagating roses.

Seedlings are planted on 18 cm between plants and 20 cm between the rows depending on varieties and desired population per hectare.

“Varieties with vigorous growth with more stems per hectare makes them more susceptible to downy mildew and botrytis, hence need more space and vice-versa,” says Mbugua.

Care for roses

Nutrition

Rose plants are heavy feeders and perform best with a steady supply of nitrogen, phosphorus and potassium. Application of both soluble and foliar fertilisers is highly recommended.

Irrigation

To bloom, the plants need consistent supply of water. In a day, every plant, needs an average 0.7 to one litre of water depending on variety and prevailing weather condition.

Mulching

Mulching is meant to suppress weeds, increase organic matter content, raise temperatures within the root zone and promote microbial activity.

Disbudding

This entails removal of side buds and is a continuous process to promote apical dominance and attain desired length and quality.

Bending

First bending is done few weeks after transplanting, and monitored throughout the cropping period. Bending’s must be kept healthy and free from pests and diseases since they act as the nutrient reserve for the rose crop.

Defoliation

This is the removal of infested, infected, dry and aged leaves and is a continuous process which aids by improving aeration to the crop, permitting proper chemical coverage and reducing pathogens.

Weeding

Weeds, in addition to competing with the rose plant for light and nutrients, also harbour pests and diseases. Weeding should be done by pulling and disposing them in a distant pit. In cases of perennial weeds, use simple tools like small forks cautiously to avoid root damage.

Pruning

This entails the removal of infected stems and blind shoots.

Pest and disease control

If you are growing roses for export, Integrated Pest Management is the preferred method of pest control to meet global gap and export guidelines.

Pests to look out for include thrips, mealy bugs, nematodes, whiteflies, caterpillars, red spider mites, scale insects and aphids.

Diseases to look out for are downy mildew, powdery mildew, crown gall, fusarium wilt, rhizoctonia, sclerotinia and Pythium-Can. You can control using Mytech (Paecilomyces linacinus) and other soil-borne diseases.

Harvesting

Disinfect harvesting tools using chlorine solution before cutting the stems to avoid disease spread such as crown gall. For newly planted crop, harvesting starts 52 days after planting. Cut stems at a height of 1cm above two leaf nodes above the cut point. Harvest stems that are 43cm, 53cm and 63cm and above. Also factor in market requirements. Remove and dispose of weak stems.

“Care should be taken to avoid bruising the flower heads as they are unmarketable.  Wrap the flower heads using nets to avoid bruising during transport to cold stores or pack-house,” advices Mbugua.

Market

According to the Kenya Flower Council, flower sales generated $960 million (about Sh109.3 billion) in 2019. Market for flowers is available both locally and internationally.

“Hotels and offices are part of my market targets. I am in the process of expanding to the export market,” says Mbugua.