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Fertilising guide

How to fertilise Green Arrow Arum (Peltandra virginica)— schedule & NPK

Also called arrow arum, tuckahoe, Virginia tuckahoe, bog onion.

More about green arrow arum

About Green Arrow Arum

Peltandra virginica · also called arrow arum, tuckahoe · flowering

Green Arrow Arum is a native North American aquatic perennial with bold, glossy arrow-shaped leaves up to 30 cm long. It thrives at pond margins or in shallow water to 20 cm deep, forms dense non-aggressive clumps, and bears greenish-white spathes in late spring. All parts contain calcium oxalate and are toxic if eaten raw.

Growth habit: Clump-forming deciduous aquatic perennial spreading by short rhizomes

What fertiliser green arrow arum actually wants — and why

Green Arrow Arum is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.

A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula.

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 green arrow arum: 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 green arrow arum, 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 green arrow arum:

Apply a slow-release aquatic tablet fertiliser into the basket in spring. Avoid over-feeding, which promotes algae growth in the pond. No feeding required in nutrient-rich natural pond mud. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.

The dormant-season rule matters more than the exact interval: skip feeding entirely when green arrow arum 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 green arrow arum

Half strength is the safe default for green arrow arum — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.

Feeding always goes onto already-damp soil, never dry roots — water green arrow arum first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the green arrow arum watering schedule.

Signs you are over-feeding green arrow arum

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for green arrow arum:

Signs you are under-feeding green arrow arum

If the symptoms point at watering, light or roots rather than nutrition, the full green arrow arum care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Flush the pot of green arrow arum with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.

Organic vs synthetic feeds for green arrow arum

Organic options

A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.

Synthetic / liquid feeds

A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.

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 green arrow arum — frequently asked questions

What fertiliser does green arrow arum need?

A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Green Arrow Arum is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.

How often should I feed green arrow arum?

Apply a slow-release aquatic tablet fertiliser into the basket in spring. Avoid over-feeding, which promotes algae growth in the pond. No feeding required in nutrient-rich natural pond mud. Apply a slow-release aquatic tablet fertiliser into the basket in spring. Avoid over-feeding, which promotes algae growth in the pond. No feeding required in nutrient-rich natural pond mud. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.

What strength of feed for green arrow arum?

Half strength is the safe default for green arrow arum — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.

What does over-feeding green arrow arum look like?

Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding green arrow arum year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.

Should I flush the soil of green arrow arum?

Flush the pot of green arrow arum with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.

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