Banana plants work in aquariums because they tolerate submersion, but they need the right setup to survive

Banana plants (Nymphoides aquatica) are aquatic plants with small, round leaves and roots that look like tiny bananas — which is where they get their name. They can live fully submerged in an aquarium, but they are not the easiest plants to keep. They need moderate to high light, stable water temperature between 72 and 82 degrees Fahrenheit, and a substrate they can root into. Many aquarists find them worth the effort because they grow slowly, do not need fertilizer in most tanks, and provide hiding spots for small fish.

The main challenge is that banana plants often arrive in poor condition from shipping, and they sometimes rot before they establish roots. If you follow the steps below, you can plant one successfully and watch it grow over several months.

Key Takeaways

  • Banana plants need to be planted in substrate — sand or gravel — with the bulbous root section partially exposed above the substrate surface.
  • They require moderate to high lighting (8 to 10 hours per day) and water temperature between 72 and 82 degrees Fahrenheit to grow.
  • New banana plants often arrive with decaying leaves or roots; remove any brown or mushy parts before planting to prevent the rot from spreading.
  • Banana plants grow slowly and do not need added fertilizer in most established aquariums, but they benefit from fish waste and organic debris in the substrate.

Inspect the plant and remove dead tissue before planting

When your banana plant arrives, examine the entire plant carefully. Look at the leaves for brown spots, slime, or mushy texture. Check the roots and the bulbous base for soft spots or dark discoloration. Banana plants often arrive with some damage because they are delicate during shipping.

Use clean scissors or a knife to remove any leaves that are more than half brown or feel slimy to the touch. Trim away any roots that are black, mushy, or falling apart. Leave the bulbous root section intact — that is where the plant stores energy and where new roots will grow. If the bulb itself is soft or smells bad, the plant may not recover, but it is worth trying to plant it anyway. Rinse the plant under cool tap water to remove any debris or algae from the nursery.

Choose a planting location in your aquarium

Banana plants grow best in the midground or background of the aquarium, where they receive moderate to high light but are not directly under the strongest light source. Place the plant where it will not be uprooted by fish digging or water flow from the filter. Many aquarists plant banana plants near the back corners or along the sides of the tank.

Avoid planting the banana plant in deep shade or in a spot where it will be buried under gravel. The plant needs light to photosynthesize, and it needs some water flow to reach its leaves. If your aquarium has a strong current from the filter, position the plant so the current does not blast directly on it — this can damage new leaves and prevent the plant from anchoring itself.

Plant the bulb in substrate with the top partially exposed

The bulbous root section is the most important part to plant correctly. Push the bulb gently into the substrate — sand or gravel — until it is about half-buried. The top half of the bulb should sit above the substrate surface. This positioning allows the bulb to absorb water and nutrients while staying exposed to light and oxygen.

Do not bury the bulb completely under the substrate. A fully buried bulb is more likely to rot because it cannot get enough oxygen. Do not leave the bulb sitting on top of the substrate either — it needs contact with the substrate to anchor and absorb nutrients. If your substrate is very fine sand, push the bulb in gently so you do not compact the sand around it. If you use gravel, the bulb will settle naturally as the gravel shifts.

Once the bulb is in place, you can gently arrange the leaves so they point upward and do not tangle with other plants or decorations. The roots will grow downward from the bulb over the next two to four weeks.

Maintain the right water conditions for growth

Banana plants need stable water temperature between 72 and 82 degrees Fahrenheit. If your aquarium is cooler than 72 degrees, the plant will grow very slowly or stop growing altogether. If the water is warmer than 82 degrees, the plant may develop algae on its leaves or decline. Use an aquarium heater to keep the temperature steady if your room temperature fluctuates.

Water hardness and pH are less critical for banana plants than temperature and light. They tolerate a wide range of pH (6.0 to 7.5) and water hardness. The most important factor after temperature is light. Banana plants need 8 to 10 hours of light per day to grow. If your aquarium light is weak or on for fewer than 8 hours, the plant will grow very slowly and may develop thin, pale leaves. Standard aquarium LED lights work well for banana plants as long as they are on for at least 8 hours daily.

Watch for new growth and remove decaying leaves

After planting, the banana plant may look the same for one to three weeks. This is normal. During this time, the plant is developing new roots in the substrate. Do not assume the plant is dead if it does not show new leaves when ready.

Once new roots establish, you will see new leaves unfurling from the center of the plant. These new leaves are usually lighter green and smaller than the original leaves. As the plant grows, the original leaves may turn brown and fall off — this is also normal. Remove any leaves that are more than half brown or falling apart, as they will decay and foul the water. Leave leaves that are mostly green, even if they have a few brown spots.

If the entire plant turns brown or mushy within two weeks of planting, the bulb likely rotted during shipping or in the tank. Remove the plant and try again with a fresh one, or consider a hardier aquatic plant like Java fern or Anubias.

Fertilizer and nutrients in established aquariums

Banana plants do not need added fertilizer in most aquariums with fish. Fish waste provides nitrogen and other nutrients that the plant can use. Decaying plant matter and uneaten food in the substrate also break down into nutrients the plant roots can absorb. If your aquarium is heavily planted or has few fish, the plant may grow more slowly, but it will still survive.

If you want to speed up growth, you can add a liquid all-in-one fertilizer once per week at half the recommended dose. Follow the product instructions carefully and do not overdose — excess fertilizer can cause algae blooms. Many aquarists find that banana plants grow fine without any added fertilizer, so this step is optional.

Frequently Asked Questions

How long does it take for a banana plant to grow new leaves?

New leaves usually appear two to four weeks after planting, once the roots have established in the substrate. Growth is slow — you may see only one or two new leaves per month. Temperature, light, and water quality all affect the speed of growth. Warmer water and stronger light lead to faster growth.

Can I plant a banana plant in sand instead of gravel?

Yes, banana plants grow well in sand. Sand is actually a good choice because it does not compact as much as gravel, and the plant roots can spread through it easily. Use aquarium sand, not play sand or construction sand, because those may contain harmful chemicals or debris.

What should I do if the banana plant bulb is soft or smells bad?

A soft or foul-smelling bulb indicates rot, which usually means the plant will not recover. You can still plant it and observe it for two to three weeks — sometimes a plant with minor rot will develop new roots and survive. If no new growth appears after three weeks, remove the plant and replace it with a hardy alternative like Java fern or Anubias.

Do banana plants need CO2 injection?

No, banana plants do not require injected carbon dioxide. They can absorb CO2 from fish waste and decaying organic matter in the water. CO2 injection may speed up growth slightly, but it is not necessary for the plant to survive and grow in a standard aquarium.

Can fish eat banana plant leaves?

Most fish do not eat banana plant leaves because they are tough and not very palatable. Herbivorous fish like plecos or some cichlids may nibble the leaves, but they usually do not cause serious damage. If you have aggressive herbivores, plant the banana plant in a spot where it is harder to reach, or choose a tougher plant like Anubias.