Ludwigia arcuata | How To Grow This Beautiful Aquarium Plant

Working on your planted freshwater aquarium and looking to add a bit of color and texture? We've got just the thing for you: Ludwigia arcuata, also known as the needle-leaf Ludwigia. Appreciated by aquarists for its lovely foliage, which shows a color gradient from green at the bottom to coppery-red at the top, this stem plant makes a great choice for the more experienced aquascaper.

Below, find out everything you need to know about Ludwigia arcuata and how to grow needle-leaf Ludwigia in your tank!

What is Ludwigia arcuata?

Ludwigia arcuata is a semi-aquatic plant in the family Onagraceae, also known as the evening primroses. It's naturally found in the southern USA—yes, an all-American aquarium plant!—where it inhabits the swampy wetlands of Alabama, Florida, Georgia, and South Carolina. Because the water levels in these habitats rise and fall with the seasons, it has adapted to grow both above and below the water line.

It's not difficult to see why Ludwigia arcuata became a classic aquarium plant. It really is very nice to look at, with the underwater version sporting delicate, narrow leaves on fine, upright stems. When the plant is grown above the water line, the leaves take on a rounder appearance (this is called heterophylly). It may even produce some lovely little yellow flowers.

Ludwigia arcuata requirements

Some guides list Ludwigia arcuata as very easy to grow, but we don't necessarily agree. Although the emersed (grown on land) form is known to be quite sturdy, the submersed (grown in water) version can be on the fragile side. It doesn't respond well to swings in the water parameters and is prone to "melting" if conditions aren't optimal.

You don't need a large tank to grow this Ludwigia. It can become quite tall, but it's not a very quick grower, so you should be able to maintain it in aquariums of 10 gallons and up with the occasional pruning. Be sure to provide plenty of light: the stems will quickly lose their bushiness and nice red coloration in low-light conditions. 50–70 µmol (8-10 hours a day) should be your minimum, though 100+ would be ideal.

Unlike good lighting, Co2 injection isn't absolutely necessary for Ludwigia arcuata, though it does help. Keep in mind that high-light tanks can become a breeding ground for algae if the Co2 and light levels don't match.

One thing you definitely shouldn't forego is a nutrient-rich substrate, as this species is a heavy root feeder. Liquid fertilizer dosing is also a good idea; go for a shrimp-safe brand like Biovert if you keep invertebrates, as the copper in normal plant foods can be deadly to them.

Tip: Prune your plants when they get too tall. Don't be afraid to give them a good snip—they'll grow back bushier than ever. You can replant the cut stems in the substrate.

Ludwigia arcuata uses

Like other stem plants, Ludwigia arcuata is mostly used in the background. You can grow it in the middle area or even the foreground of your tank as well, but keep in mind this might mean frequent pruning will be necessary to keep it from growing too tall!

Because it can also grow emersed, needle-leaf Ludwigia is suitable for paludariums. When grown on land, it will take on a more creeping (rather than upright or bushy) growth pattern.

Buying Ludwigia arcuata

This is a relatively popular aquarium plant, so you should have no problem finding it in your local aquarium store. And if you don't want to go out, you can even buy it online! The Shrimp Farm offers bunches of three Ludwigia arcuata stems and ships 'em right to your doorstep, no hassle.

Tip: Your plant may "melt" somewhat after buying it and planting it in your tank. This is normal: it has to adapt to its new environment, especially if it was previously grown emersed. Just wait! It should bounce back soon.