Dwarf Onion Plant Care – Is It Good For Fish Tank?

A Dwarf Onion plant also called a Dwarf Water Onion plant, is a pretty interesting plant to have in your freshwater aquarium. You can find dwarf onion plants in fish stores alongside freshwater aquarium plants. Yet, much like the White Sanderiana plant, it is not a natural aquatic plant.

A terrarium or a pond is an excellent place to grow dwarf onion. But, you can still grow them in your freshwater tank if you like how they look. A dwarf onion plant adds a nice green color to the background. Amano shrimp and Red Cherry Shrimp like to climb up and down the plant, nipping at the edible matter. But, the plant won’t last long in an aquarium.

Dwarf Onion Plant vs. Water Onion Plant

A dwarf onion plant, Zephyranthes candida, is often called a “dwarf water onion.” The name may make it difficult to tell the difference from a similar-looking onion plant fish stores sell known as a “water onion,” Crinum thaianum.

Both plants have white bulbs with roots on the bottom. The stems are different, but they are both green. A dwarf onion plant stem looks more like a green tube. A water onion looks more like a crabgrass leaf. Despite their names, Dwarf Onion plants are not for eating. They are not actual onions.

Dwarf Onion Plant
Dwarf Onion Plant with visible roots, bulbs and stems

Dwarf Onion Plant Roots, Bulb & Stem

A dwarf onion plant has roots, a bulb, and a stem. Roots grow down from the bottom of the bulb and are white. When they die, they turn brown and lose their firmness. As the roots decay, they look like strands of wet brown paper.

A dwarf onion plant bulb is small at first and grows to be the size of a dime. It’s white and hard. A brown membrane may cover the plant bulb as it grows. The bulb will have a round form, with flattened bottoms, circular centers, and taper tips on top.

A dwarf onion plant grows smaller offshoot bulbs around the base of the main bulb. The smaller bulbs soon become separate from the main bulb. They root themselves and become their own plants. The parent bulb continues to grow as if nothing happened.

A dwarf onion plant has green, strong stems that grow up from the bulb to the water. These stems are beautiful because they stand straight up and look nice in the backdrop.

But, if you are going for a “forest look,” you may use the plant in the foreground. The tips of the stems might become yellow or orange-ish in color. Snip off the discolored end of the stem. Minor trimmings do not appear to affect the plants.

Proper Dwarf Onion Plant Care

Although the dwarf onion plant is a terrarium plant, it may survive in an aquarium as a cluster of dwarf onions. Dwarf onions can grow well, for a while, in water that is around 78 degrees Fahrenheit. The pH of the water should be on the alkaline side at 7.4, and there should be moderate to high light.

How To Plant Dwarf Onions In Aquarium

Planting dwarf onion bulbs can be tricky. It is tempting to plant the onion bulb deep in the soil to stop it from floating. But it would be best if you did not put it too deeply because then the onion bulb would die.

Plant the bulbs at least 1/3 of their depth into the substrate. You should be able to see the bulbs. The whole process may be frustrating because the bulb roots may not be strong enough to hold the plant in place. But you will need to keep trying for a while until the roots grow. You will know when they are strong enough by how deep they dig into the substrate.