Cassava /Manihot Esculenta/
Cassava is a short-lived perennial shrub, growing up to four metres in height with long knobbly stems and deeply lobed leaves (like a papaya). It produces an abundance of large tuberous white or yellow-fleshed roots that are a staple around the world. Long tubers fan out from the central stem in all directions.
Edible parts and usage
There are both sweet and bitter varieties of cassava.
The sweet has edible roots while the bitter requires lengthy processing and is suited for making cassava flour or tapioca. For the best tasting varieties, obtain cassava from someone growing plants they are already eating from.
Once harvested, the roots deteriorate rapidly and must be cooked or frozen within 24hrs.
Purple streaks indicate hydrocyanic acid and should be discarded.
Surplus tubers can be stored by grating and freezing.
Roots can be fried as chips, boiled and salted, grated and used in cakes or ground for flour.
Cassava must always be cooked and the outer skin must be removed, as it is inedible. The easiest way to remove the skin is to run a blunt knife down the side of the tuber and carefully peel the skin off. If it is hard to peel, it may be an older tuber. These are edible but more fibrous so aim to harvest earlier next time.
The top 4-6 leaves of each stem are eaten as a tasty green and are at their most tender in the wet season. Cassava leaves must be cooked for at least 15mins, then discard the water to remove the hydrocyanic acid. The leaves have a great texture and are often served with coconut milk and chilli.
Subtropics to tropics
Grow cassava in fertile soil for best results. Planted in Spring/Summer or early Autumn after good rain it will need little care. Plants grown in friable soil are easier to lift out of the ground at harvest.
The woody stems of mature plants are cut into 30cm cuttings.
Remove all the leaves and plant on an angle at 1/2 their length.
Space plants at 60-100cm apart.
Stems must be planted with at least two buds underground for good root formation.
Stems planted crosswise will grow into a living fence and can be kept compact by regularly tipping the plant and harvesting leaves.
Risks and weed potential
Harvesting & Processing
Harvest roots after 8-10 months.
One sign of maturity is the plant flowering.
Otherwise from about 8 months you can scrape the soil away at the base of the plant to reveal the swollen tubers. If they are at least 5cm they are ready to harvest. The whole plant can be harvested at once or individual roots can be ‘bandicooted’ and the rest left to grow on.
Harvest tubers by lifting the plant from the base. Plants grown from cuttings and planted on an angle are easy to harvest. Simply lever the stem towards you, lifting the tubers free from the soil.
Make sure to dig up any tubers left behind.