Cassava (Manioc) care

Light

Cassava needs sun on the leaves, not just bright ambient room light. Full sun is non-negotiable — 8+ hours daily. A warmth-loving tropical crop; in the UK it requires a heated greenhouse with supplemental lighting or a very long warm polytunnel season. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.

Watering

Outdoor cassava crops want water every 7-14 days once established; cassava is notably drought-tolerant. The single best habit is a finger-test before watering — push a finger 3-4 cm into the soil. Damp = wait a day; dust-dry = water deeply at the base of the plant. Once established, cassava tolerates extended dry periods far better than most food crops. Overwatering is a greater risk than underwatering; waterlogged soil causes root rot and cyanide accumulation. Allow the soil to partially dry between waterings.

Soil and pot

Cassava grows best in light, well-drained, sandy or loamy soil of moderate fertility. Cassava thrives in poor, infertile soils where other crops fail, but does require good drainage. Avoid heavy clays and waterlogged sites. pH 5.5–7.0. Do not over-fertilise with nitrogen. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Cassava sits happiest at around 60-80% humidity and 25-35°C (77-95°F). Tropical humidity is preferred but cassava tolerates drier conditions once established. High humidity can promote fungal leaf diseases such as cassava bacterial blight. Good air circulation is beneficial. If you keep the room above 25 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed cassava sparingly. Cassava grows in poor soils but benefits from a moderate application of balanced NPK fertiliser (avoiding excess nitrogen) at planting, and a potassium-rich top-dress midway through the growing season to support root bulk. Over-fertilising promotes leafy growth over root development. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on cassava in the Growli community. Each is annotated with the most common cause so you know where to start.

• Cassava mosaic disease — Caused by begomovirus spread by whitefly; causes leaf mottling, distortion, and severe yield loss. Use virus-free planting material and control whitefly populations.
• Cassava bacterial blight (CBB) — Xanthomonas axonopodis causes leaf spots, stem die-back, and root rot. Use certified disease-free cuttings; remove affected material promptly.
• Mealybugs — Colonies on stems and root crowns stunt growth. Introduce parasitic wasps (Anagyrus lopezi) as biological control; use neem oil for minor infestations.
• Root rot in waterlogged soils — Elevated cyanide content and Phytophthora root rot occur in wet conditions. Excellent drainage is the primary preventive measure.
• Tuber cracking — Caused by irregular soil moisture or excessive nitrogen. Maintain consistent soil moisture and avoid over-fertilising.

Companion plants

Cassava pairs well with Cowpea, Maize, Sweet potato, and Groundnut. These are species with similar light and water needs, so you can grow them in the same bed or container without conflict.

Propagation

Propagate exclusively from stem cuttings (stakes) 20-30 cm long with several nodes. Plant diagonally or horizontally in mounds. Cuttings from healthy, disease-free mother plants are essential. Germinates in 7-14 days; tubers are ready to harvest after 9-24 months depending on variety and climate. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Cassava is toxic to pets. All parts of Manihot esculenta contain cyanogenic glycosides (linamarin and lotaustralin) that release hydrogen cyanide when chewed or damaged — toxic to dogs, cats, and humans if consumed raw. The ASPCA lists the genus as toxic. Proper processing (peeling, soaking, cooking) detoxifies edible roots for human consumption, but unprocessed plant material must be kept away from pets. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Cassava deep-dive guides

Every aspect of cassava care, each with its own calibrated guide:

• Common cassava problems & fixes
• Cassava watering schedule
• Cassava light requirements
• Best soil mix for cassava
• Cassava fertilizing guide
• When to repot cassava
• How to propagate cassava
• How to prune cassava
• What's eating my cassava?
• Cassava growth rate & size
• Cassava cold hardiness
• Cassava temperature & humidity
• Is cassava toxic to cats & dogs?
• Is cassava toxic to cats?
• Is cassava toxic to dogs?

Related guides

Cassava is also known as Manioc, Yuca, Tapioca plant, and Brazilian arrowroot.

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• All 11687 plant care guides in the Growli library