Fresh Asparagus [iStockphoto]

Asparagus is a perennial vegetable that is gaining popularity in Kenya due to its nutritious and medicinal benefits. Being a perennial plant means you can harvest for many years without replanting. Growing asparagus requires some patience, as it typically takes a couple of years for the plants to become established before you can start harvesting a significant crop.

Depending on growth and climatic factors, you can harvest asparagus from the same plant for 15 to 20 years and in some cases up to 30 years. Daniel Kinyanjui, a farmer from Molo says varieties found in Kenya are Mary Washington, Jersey Giant F1 and Jersey King F1. He gives a step-by-step guide to farming asparagus.

Choose a suitable location: Asparagus plants thrive in well-drained soil with plenty of sunlight. Select a spot in your garden that receives full sun and has soil that drains well.

Prepare the soil: Asparagus prefers soil that is slightly acidic to neutral (pH 6.0 to 7.0). Before planting, amend the soil with plenty of organic matter, such as compost or well-rotted manure, to improve fertility and drainage.

Planting: Asparagus is typically grown from crowns (one-year-old asparagus plants) rather than seeds.  “If you are looking for seeds visit Continental seeds, they get them from the US, and,” he said. Plant the crowns as soon as the soil can be worked. Dig trenches about eight to 10 inches deep and 12 to 18 inches wide.  “Space the crowns about 12-18 inches apart within the trench, and cover them with about two inches of soil. As the plants grow, gradually fill in the trench until it is level with the surrounding soil,” says Kinyanjui.

Watering: Keep the soil consistently moist, especially during the first growing season. Apply a layer of organic mulch, such as straw or shredded leaves, around the asparagus plants to help retain moisture, suppress weeds, and moderate soil temperature. Asparagus is a heavy feeder and benefits from regular fertilization. Before the spears emerge, apply a balanced fertilizer according to the package instructions. Additionally, side-dress the plants with compost or well-rotted manure during the growing season.

Pest and disease management: Keep an eye out for common pests and diseases that can affect asparagus, such as asparagus beetles and fungal diseases. Practise good garden hygiene and promptly remove any affected plants or debris to prevent the spread of pests and diseases.

Harvesting: Avoid harvesting any spears during the first year to allow the plants to establish a strong root system. In the second year, you can harvest spears for about two to three weeks, and in subsequent years, you can extend the harvest period to six to eight weeks.

Maintenance: After the last harvest of the season, allow the remaining spears to grow and leaf out. These fern-like foliage will photosynthesize and provide energy to the roots for next year's crop. 

Market: Asparagus is mainly grown for export and to a small extent for local consumption. Depending on quality and availability, asparagus retails at Sh300 to Sh1,000 per kilogramme.