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 conventional small-scale hydroponics, but relevant to outdoor aquaponics in tropical regions. The large root system and 8-18 month growing cycle require in-ground planting or very large containers (60 L). Propagation is by stem cuttings (20–30 cm pieces of mature stem pushed into moist soil at an angle), not seeds. Temperature: 25–35°C year-round (strictly tropical; dies below 10°C). Full sun (DLI 20+ mol/m2/day). pH 5.5-6.5 (tolerates acidic conditions that most crops cannot). The plant is a light feeder by tropical crop standards and grows in nutrient-poor conditions, but responds to fertilization with increased root yield. Harvest when roots are full-sized (8-18 months from planting depending on variety). Critical safety note: bitter cassava varieties contain toxic levels of cyanogenic glycosides and must be processed (peeled, soaked, fermented, and/or dried) before eating. Consuming inadequately processed bitter cassava can cause cyanide poisoning. Sweet varieties require only peeling and cooking (boiling, frying, or roasting). For tropical aquaponics, cassava planted in beds irrigated by fish system effluent produces well and makes efficient 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. |