Cassava
Manihot esculenta
Also known asYuca · Manioc · Tapioca plant · Mandioca · Mogo · Aipim · Kappa
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 9–13 (winter low around -7°C)
- Frost
- frost sensitive (dies at first frost)
- Season
- year-round tropical
Growing systems
Root mass: very heavy. Thin-channel systems can't hold this crop.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Soil-based mix (Potting soil) | varies | high | high |
Nutrient demand by stage
NPK ratios are relative weights. EC targets shift through the plant's life.
| Stage | N | P | K | EC (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 0.8 |
| vegetative | 2 | 1 | 3 | 1.6 |
Companion-growing notes
- Heavy uptake of potassium. Co-grown crops with the same demand will end up deficient even at "correct" EC.
Aquaponics suitability
Not recommended
Fish waste alone doesn't supply enough of what this crop demands. Grows in hybrid systems with supplemental dosing, but expect active management.
Care notes
A tropical crop not suited to small-scale hydroponics, but relevant to outdoor aquaponics in the tropics. The big root system and long 8 to 18 month cycle call for in-ground planting or very large containers (around 60 L). It is propagated from stem cuttings, 20–30 cm pieces of mature stem pushed into moist soil at an angle, not from seed. Keep it at 25–35°C year-round; it is strictly tropical and dies below 10°C. Give full sun, 20 or more mol/m2/day, at pH 5.5-6.5, where it tolerates acidity most crops cannot. It is a light feeder by tropical standards and grows in poor ground, but fertiliser raises root yield. Harvest when roots are full-sized, 8 to 18 months from planting. The critical safety point: bitter cassava holds toxic cyanogenic glycosides and must be peeled, soaked, fermented and/or dried before eating, since inadequately processed bitter cassava can cause cyanide poisoning, while sweet varieties need only peeling and cooking. In tropical aquaponics, cassava in effluent-irrigated beds makes good use of the warm, nutrient-rich water.
Notable varieties
| Cultivar | Type | Days | Notes |
|---|---|---|---|
| Sweet (low-cyanide) | open pollinated | 270 | Selections with cyanogenic glycoside levels below about 50 mg/kg fresh weight, considered safe with thorough cooking alone (no fermentation needed). Examples include CMC-40, MCol-2215, and many home-grower varieties. Most commercial yuca sold for table use is from this group. |
| Bitter (high-cyanide) | open pollinated | 365 | Industrial and traditional-staple cultivars with cyanogenic glycosides over 100 mg/kg fresh weight. Requires soaking, fermentation, or grating-and-pressing to detoxify; not for casual home use. The basis for cassava flour and gari and tapioca production where industrial processing handles the cyanide. |