Vegetable · Euphorbiaceae
Cassava
Manihot esculenta
A forgiving tropical staple that rewards patience, as long as you process the roots with care.
Full sun
Every 7–14 days
59–95°F · 15–35°C
240–360 days
Overview
If you are new to growing your own food, cassava (Manihot esculenta) is a kind plant to start with. It is a woody tropical shrub in the spurge family (Euphorbiaceae), and it has fed people in warm regions for thousands of years. Native to South America, it has become one of the world's most relied-upon staple crops, valued for the starchy roots it tucks away underground.
Part of what makes this plant so encouraging is how little fuss it asks for. Once it has settled in, cassava shrugs off dry spells with ease and keeps growing where many crops would struggle. It reaches 5 to 10 feet (1.5 to 3 m) tall and spreads 3 to 6 feet (90 to 180 cm), filling out at a steady, manageable pace that gives you time to learn alongside it.
The one rule worth taking to heart is about the harvest, not the growing. Every part of cassava holds cyanide-forming compounds, so the roots and leaves are only safe after they are peeled, soaked or grated, and thoroughly cooked. Handle that step with respect and the rest of the journey is gentle and rewarding, with plenty of room for small mistakes along the way.
Care
The short version: give cassava full sun, well-drained sandy loam, and warmth, and it will largely look after itself. Water young plants while they settle, then ease right back, since this is a drought-tolerant plant once established. Keep it out of frost, lift the roots before the cold arrives, and always peel, soak or grate, and cook the roots before eating.
Light
Cassava is happiest in full sun, soaking up as much light as you can give it. It will also get along in partial shade if that is what your garden offers, so there is room to work with the spot you have.
Water
Go gently here. Water young plants steadily while they find their feet, then ease right back, because cassava is highly drought-tolerant once established and only really needs a drink every 7 to 14 days in dry spells. Let the top 3cm dry between waterings, and steer clear of soggy ground, which invites root rot and softens the tubers.
Soil
Aim for well-drained sandy loam with a pH of 5.5 to 6.5. The most important thing is that water can move through freely, since cassava far prefers dry feet to wet ones.
Temperature
Warmth is the key to keeping this plant content, with an ideal range of 59°F to 95°F (15°C to 35°C). It is frost-tender, though, and even a light frost will blacken the foliage, so keep it well within the warm part of the year.
Humidity
Cassava is relaxed about moisture in the air, sitting comfortably in 40% to 70% humidity and coping happily with drier conditions. This is one less thing for you to worry about.
Feeding
Feeding cassava is refreshingly simple. Work in a balanced NPK with adequate potassium for root development right at planting, and that single feeding is generally all it needs to support good root growth.
Pruning
Very little pruning is called for. Trim away the lower lateral shoots to keep energy focused, and cut back any frost-killed or damaged stems. Save healthy stems at the end of the season, since they become your cuttings for next year.
Repotting
not typically container-grown
Size & spacing
Give each plant room to reach its full 5 to 10 feet (1.5 to 3 m) in height and 3 to 6 feet (90 to 180 cm) across. It grows at a moderate pace and lives as a perennial outdoors, so a little planning now leaves it space to thrive.
When to plant
Timing with cassava is forgiving as long as you respect the warm season. You plant your stem cuttings once frost has passed and the soil has warmed, then settle in for a long, patient wait while the roots bulk up underground.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Plant woody stem cuttings (stakes) after all danger of frost has passed and soil is warm.
- Harvest: Harvest roots 8-18 months after planting, once tubers have bulked.
Hardiness
USDA hardiness zones: 9–11
Temperature: down to -7°C
Troubleshooting
Most problems with cassava are easy to read and easy to recover from once you know the signs. Below are the few issues you are most likely to meet, each with a clear path back to healthy plants.
Mottled, twisted leaves point to a virus
When the foliage turns blotchy yellow-green, puckers, and the whole plant seems to stall, you are most likely looking at cassava mosaic virus. There is no cure, so the kindest thing for the rest of your patch is to pull the affected plants and start fresh. Reach for certified virus-free stakes next time and keep whiteflies in check, and you will be back on solid ground.
Fix:
- Remove and destroy infected plants
- Use virus-free planting material
- Control whitefly vectors
Blackened stems after a cold night
A night near freezing can leave the leaves and stems darkened and limp, since this is a frost-tender plant at heart. Take it as a clear signal to lift your roots before the cold arrives. In all but the warmest zones, simply treating cassava as a single warm-season crop keeps everything easy and forgiving, and your roots stay safe underground.
Fix:
- Harvest roots before frost
- Protect or relocate if possible
Soft, smelly tubers usually mean wet feet
If you dig and find roots that are mushy, off-color, and unpleasant to the nose while the plant droops above ground, soggy soil is the likely culprit. The good news is this is preventable. Plant on ridges or a well-drained spot, ease back on watering, and lift the roots as soon as they have bulked, and your harvest should come up clean and sound.
Fix:
- Improve drainage
- Avoid overwatering
- Harvest promptly once mature
Toxicity
This is the one area where cassava asks for real care, so it is worth slowing down and reading closely. Every part of the plant can release cyanide when raw or under-processed, which makes it genuinely dangerous to people and animals until it is properly prepared.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Severe
A cat that has chewed raw cassava may drool, vomit, and breathe with effort. Watch too for dilated pupils, weakness, convulsions, and collapse, and call your vet right away.
Dogs Severe
In dogs, look for drooling, vomiting, and labored breathing, sometimes alongside staggering and seizures. Treat any of these as an emergency and head to the vet.
Horses Toxic
Horses can show fast, distressed breathing, trembling, and stumbling. Because a large dose can be fatal, do not wait to seek veterinary help.
Rabbits Toxic
Rabbits are small, so their bodies handle cyanide poorly. Weakness, gasping, and twitching are warning signs that need prompt attention.
Livestock Severe
Cattle, goats, and sheep may breathe rapidly, drool, stagger, and develop muscle tremors, then convulsions and collapse. Keep raw plant material well out of their reach.
Birds Toxic
Poultry and pet birds may show labored breathing and sudden weakness. Their small size means even a modest amount can become serious quickly.
People Caution
Cassava feeds millions, but only after it is peeled, grated or soaked, and cooked. Raw or half-processed roots and leaves release cyanide that can bring on vomiting and dizziness, and steady under-processing can lead to the lasting paralysis known as konzo. Never eat any part raw.
Proper processing (peeling, grating/soaking, and thorough cooking) drives off the cyanide and renders cassava safe to eat; the raw plant and unprocessed roots/leaves are dangerous. Keep raw plant material away from children and animals.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
You will mainly come across two kinds of cassava, and the difference between them comes down to how much processing each one needs before it is safe to eat.
Sweet cassava
This kind carries fewer cyanide-forming compounds, and most of what it does hold sits in the peel. It still asks to be peeled and cooked before it reaches the table.
Bitter cassava
Here the cyanide-forming compounds run throughout the root, so it calls for heavier processing: grating, soaking, fermenting, and cooking before it is safe to eat.
How to propagate
Making more cassava is one of the most reassuring parts of growing it, because you simply replant pieces of the stems you already have. It roots readily, so this is a great place for a first-time grower to build confidence.
Stem cuttingsEasy
Plant mature woody stem cuttings (stakes) at the start of the warm season after frost danger has passed. · 2 to 4 weeks for sprouting and rooting
This is a wonderfully forgiving way to multiply your plants. Cut stakes 20 to 30 cm long from mature, healthy stems, set them out as the warm season begins, and you should see fresh shoots and roots in about 2 to 4 weeks. No seeds or tubers needed, just stems.
Myths
A quick boil makes any cassava safe to eat.
Bitter types ask for more than a fast boil; they need peeling, grating, soaking, and a long cook to be safe. A brief boil leaves too much cyanide behind, and under-processing over time can lead to cyanide poisoning and the paralysis called konzo.
Only the roots of cassava are poisonous.
The leaves carry the same cyanide-forming compounds as the roots. Both need proper processing before any person or animal can safely eat them.