Fertilising guide
How to fertilise Colocasia Antiquorum (Colocasia antiquorum)— schedule & NPK
Also called dasheen, old-world taro.
More about colocasia antiquorum
About Colocasia Antiquorum
Colocasia antiquorum · also called dasheen, old-world taro · edible
Colocasia antiquorum, the old-world dasheen taro, is a heat-loving aroid grown for its starchy corms and downward-pointing peltate leaves. It thrives in warm, swampy, fertile ground with constant moisture and high humidity, growing fast in a single season. All raw parts contain calcium oxalate and must be thoroughly cooked before eating.
Growth habit: Clumping herbaceous perennial growing from a central corm with downward-pointing (peltate) heart-shaped leaves on succulent stalks; spreads by offset cormels.
Watch for — Stunted or small corms: Too little sun, a short cool season, or insufficient feeding produces tiny corms; give full sun, a long warm season and rich soil.
What fertiliser colocasia antiquorum actually wants — and why
Colocasia Antiquorum feeds in two distinct phases — balanced to build the plant, then high-potassium the moment flowering starts to set and fill a heavy crop.
Balanced (even N-P-K) at planting for roots and frame, then switch to a high-potassium ("high-potash") tomato-style feed once the first flowers open — potassium is what sizes and ripens fruit, not nitrogen.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for colocasia antiquorum: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed colocasia antiquorum, and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For colocasia antiquorum:
Heavy feeder. Apply a balanced or slightly nitrogen-rich fertiliser every 3-4 weeks through the growing season, easing off as corms mature in late summer to favour starch storage over leaf growth. So: a balanced feed or compost at planting, then a high-potash liquid every 1-2 weeks from first flower through harvest across the main season (spring through early autumn).
The dormant-season rule matters more than the exact interval: skip feeding entirely when colocasia antiquorum is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for colocasia antiquorum
Follow the crop-feed label rate for colocasia antiquorum — these are calibrated for hungry vegetables. Consistency through fruiting matters more than strength; erratic feeding causes problems like blossom-end rot.
Feeding always goes onto already-damp soil, never dry roots — water colocasia antiquorum first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the colocasia antiquorum watering schedule.
Signs you are over-feeding colocasia antiquorum
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for colocasia antiquorum:
- Vigorous dark-green leafy growth but few flowers or fruit (excess nitrogen).
- Lush foliage hiding the crop; soft growth prone to pests and disease.
- Salt crust on the soil and scorched leaf edges in containers.
Signs you are under-feeding colocasia antiquorum
- Pale, yellowing lower leaves and stunted growth.
- Small fruit, poor set, and a quickly exhausted plant.
- Blossom-end rot and weak cropping from erratic or insufficient feeding.
If the symptoms point at watering, light or roots rather than nutrition, the full colocasia antiquorum care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
In containers, fertiliser salts build up fast — water colocasia antiquorum thoroughly so excess drains from the base each time, and flush pots with plain water every few weeks to prevent a damaging salt build-up.
Organic vs synthetic feeds for colocasia antiquorum
Organic options
Garden compost or well-rotted manure dug in before planting, plus a liquid comfrey or seaweed feed once fruiting starts. UK: comfrey feed or organic Tomorite; US: Espoma Tomato-tone or Neptune's Harvest. Builds soil and feeds in one.
Synthetic / liquid feeds
A balanced feed at planting then a high-potash tomato feed in fruiting — UK: Growmore at planting then Tomorite (Levington) or Phostrogen; US: a balanced 10-10-10 then Miracle-Gro Tomato or a bloom booster.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising colocasia antiquorum — frequently asked questions
What fertiliser does colocasia antiquorum need?
Balanced (even N-P-K) at planting for roots and frame, then switch to a high-potassium ("high-potash") tomato-style feed once the first flowers open — potassium is what sizes and ripens fruit, not nitrogen. Colocasia Antiquorum feeds in two distinct phases — balanced to build the plant, then high-potassium the moment flowering starts to set and fill a heavy crop.
How often should I feed colocasia antiquorum?
Heavy feeder. Apply a balanced or slightly nitrogen-rich fertiliser every 3-4 weeks through the growing season, easing off as corms mature in late summer to favour starch storage over leaf growth. Heavy feeder. Apply a balanced or slightly nitrogen-rich fertiliser every 3-4 weeks through the growing season, easing off as corms mature in late summer to favour starch storage over leaf growth. So: a balanced feed or compost at planting, then a high-potash liquid every 1-2 weeks from first flower through harvest across the main season (spring through early autumn).
What strength of feed for colocasia antiquorum?
Follow the crop-feed label rate for colocasia antiquorum — these are calibrated for hungry vegetables. Consistency through fruiting matters more than strength; erratic feeding causes problems like blossom-end rot.
What does over-feeding colocasia antiquorum look like?
Vigorous dark-green leafy growth but few flowers or fruit (excess nitrogen). Lush foliage hiding the crop; soft growth prone to pests and disease. Salt crust on the soil and scorched leaf edges in containers. Staying on a high-nitrogen feed once colocasia antiquorum starts flowering is the classic error — you get a huge leafy plant and a disappointing crop. Switch to high-potash the moment flowers appear.
Should I flush the soil of colocasia antiquorum?
In containers, fertiliser salts build up fast — water colocasia antiquorum thoroughly so excess drains from the base each time, and flush pots with plain water every few weeks to prevent a damaging salt build-up.
Keep reading
- Colocasia Antiquorum care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water colocasia antiquorum — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise tomato
- How to fertilise pepper
- How to fertilise cucumber
- All 2464 fertilising guides in the Growli library