Fertilising guide
How to fertilise Maranta Arundinacea (Maranta arundinacea)— schedule & NPK
Also called arrowroot, West Indian arrowroot.
More about maranta arundinacea
About Maranta Arundinacea
Maranta arundinacea · also called arrowroot, West Indian arrowroot · edible
Maranta arundinacea, West Indian arrowroot, is a tropical rhizomatous perennial grown both as an edible crop and a leafy houseplant. Its starchy rhizomes are the source of culinary arrowroot powder, an easily digested thickener. Taller and plainer-leaved than ornamental marantas, it needs warmth, plenty of moisture and a long frost-free season to bulk up its rhizomes.
Growth habit: Upright, clump-forming herbaceous perennial growing from fleshy, starchy rhizomes; broad ovate green leaves on tall stems, with the rhizomes harvested for arrowroot starch.
Watch for — Poor rhizome yield: Insufficient warmth, water or feeding limits the harvest. Give a long frost-free season, rich moist soil and generous feeding for plump rhizomes.
What fertiliser maranta arundinacea actually wants — and why
Maranta Arundinacea 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 maranta arundinacea: 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 maranta arundinacea, 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 maranta arundinacea:
Feed a fertile crop generously: work compost or a balanced fertiliser into the soil at planting and side-dress or liquid-feed through the growing season. For houseplants, a balanced feed monthly in spring and summer. 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 maranta arundinacea 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 maranta arundinacea
Follow the crop-feed label rate for maranta arundinacea — 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 maranta arundinacea first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the maranta arundinacea watering schedule.
Signs you are over-feeding maranta arundinacea
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for maranta arundinacea:
- 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 maranta arundinacea
- 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 maranta arundinacea 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 maranta arundinacea 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 maranta arundinacea
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 maranta arundinacea — frequently asked questions
What fertiliser does maranta arundinacea 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. Maranta Arundinacea 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 maranta arundinacea?
Feed a fertile crop generously: work compost or a balanced fertiliser into the soil at planting and side-dress or liquid-feed through the growing season. For houseplants, a balanced feed monthly in spring and summer. Feed a fertile crop generously: work compost or a balanced fertiliser into the soil at planting and side-dress or liquid-feed through the growing season. For houseplants, a balanced feed monthly in spring and summer. 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 maranta arundinacea?
Follow the crop-feed label rate for maranta arundinacea — 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 maranta arundinacea 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 maranta arundinacea 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 maranta arundinacea?
In containers, fertiliser salts build up fast — water maranta arundinacea 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
- Maranta Arundinacea care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water maranta arundinacea — 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