TankBud

Giant sagittaria

Sagittaria platyphylla

Also known as Broadleaf sagittaria, Delta arrowhead, Slender arrowhead, Giant sag

FreshwaterRosetteRunners

Invasive. Giant sagittaria is invasive and regulated in parts of Australia and some US states. Never release into the wild; dispose of in the trash.

Giant sagittaria (Sagittaria platyphylla)
Show_ryu · CC BY-SA 3.0

Care at a glance

Light
Medium light
CO2
No CO₂ needed
Temperature
68–79°F
20–26°C
Max height
15.7 in
40 cm
Growth rate
Medium
Placement
Midground
Type
Rosette
pH
5.7–8.0
Hardness
2–15 dGH
Spread
7.9 in (20 cm)
Nutrient uptake
Root feeder
Growth region
Submersed or emersed
Difficulty
Easy
Family
Alismataceae
Origin
Southeastern and central United States (and Mexico)

Overview

Giant sagittaria is one of the easier rosette plants and a good choice for a low-tech tank. Its grass-like leaves fill the midground.

Did you know

The runner habit that makes giant sagittaria useful in an aquarium also made it one of Australia's worst aquatic weeds. After escaping from ornamental ponds, it choked irrigation channels and pushed out native wetland plants.

Caring for giant sagittaria

Plant giant sagittaria in the midground with the roots buried and the crown just above the substrate. It feeds mainly through its roots, so give it a nutrient-rich substrate or root tabs. Add enough iron to keep the leaves green.

It needs no added CO2 and does well in medium light at 68 to 79°F (20 to 26°C). Under strong light it stays compact and grassy at 15 to 25 cm. In dim tanks the leaves stretch tall and floppy, reaching for the surface.

It grows at a medium pace and runs freely across open substrate by runners. Pull stray plantlets to keep a tidy midground clump rather than a spreading lawn. Dispose of the trimmings responsibly and never release it.

Good to know

Giant sagittaria is a member of the arrowhead family, Alismataceae. Like other Sagittaria, it grows distinct submersed and emersed leaf forms. The submersed leaves are long, strap-like and grassy, without the classic arrow shape, while the emersed ones are broader and lance-shaped. It bears whorls of white three-petaled flowers on emergent stalks and reproduces by seed and by tuber-tipped stolons.

In the wild

Giant sagittaria is native to the southeastern and central United States, including Louisiana, Florida, Mississippi and neighboring states, and to Mexico. It is an emergent marsh plant of ditches, canals and slow-moving rivers, spreading across shallow margins by runners. Outside its native range it is a serious invasive weed. Australia has declared it a Weed of National Significance, and several states there restrict or prohibit its sale.

Common questions

Does giant sagittaria need to be planted in the substrate?

Yes. Bury the roots and leave the crown, where the leaves join, just above the substrate.

Does giant sagittaria need CO2?

No. Giant sagittaria grows well without added CO2.

How much light does giant sagittaria need?

Giant sagittaria wants medium light. A light sold for planted tanks covers it.

Does giant sagittaria need root tabs?

Yes. Giant sagittaria draws much of its food through its roots. Push root tabs in near it, or grow it in a nutrient-rich soil.

How do you propagate giant sagittaria?

Giant sagittaria propagates by runners. New plants grow along its runners. Cut one free once it has roots and plant it.

How tall does giant sagittaria grow?

Giant sagittaria grows to about 15.7 in (40 cm) tall. It grows at a moderate pace.

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