Have you ever wished for an aquarium plant whose colorful leaves could provide a beautiful foil for the green plants that surround it? Look no further than the Ludwigia family.
With their red leaves and stems, Ludwigia plants provide vibrant bursts of color to add diversity and interest to the planted aquarium.
Ludwigia palustris is one of the easier-to-grow members of the genus and is a great plant for beginners looking to grow their first red plants, as well as advanced aquarists looking to give their aquascape the edge.
Ludwigia Palustris Plant Profile at a Glance
| Ludwigia Palustris Info | |
|---|---|
| Scientific Name | Ludwigia palustris |
| Other Names | Some consider it the same species as Ludwigia natans |
| Difficulty | Easy |
| Lighting | Medium-Strong |
| Optimal pH | 6-8 |
| Optimal GH | 2-30 dGH |
| Water Temperature | 68 – 82 °F (20 – 28 °C) |
| Substrate | Aquarium soil or gravel |
| Growth Rate | Moderate |
| Aquascape Placement | Mid-ground and background |
| Size | 4-12 inches |
| Fertilizers | Micronutrients may be helpful |
| CO2 | Not necessary / Optional |
| Propagation | Stem cuttings |
| Color | Green to red, depending on conditions |
Origins and Background
Ludwigia palustris is a popular red-leaved plant that’s often grown in freshwater aquariums and terrariums around the world. The species is native and widespread across North America.
Its Latin species name ‘palustris’ tells us that it grows in marshes in the wild, but it can also grow in floodplains and shallow rivers. Ludwigia palustris can grow on land as long as its roots remain in damp soil.
It’s closely related to other aquarium plants in the same family such as Ludwigia repens and Ludwigia arcuata, and Ludwigia natans. There is even some debate within the scientific community about whether some Ludwigia species should be considered synonymous.
Appearance
A prostrate, herbaceous perennial with small elliptic leaves, Ludwigia palustris is an attractive aquarium plant whose red hues will add contrast and vibrancy to your fish tank or terrarium.
Some cultivars have been developed to produce even brighter, uniform red leaves, compared to the regular species which often has more mottled green-red leaves.
Size and Growth Rate
Ludwigia palustris is a medium-sized aquarium plant, typically growing from 4 – 12 inches tall.
This may be an asset for those looking for less vigorous aquarium plants, and this species tends to grow more slowly and to a smaller size than its cousin Ludwigia repens.
Under optimum conditions, given plentiful light, nutrients, and CO2, however, the plant can reach 20 inches in height.
Flowers
Like other Ludwigia species, Ludwigia palustris is a flowering plant – but don’t expect fireworks! The flowers of Ludwigia palustris are very small and modest, with four petals.
The flower bracts are green, and the petals are white. Each flower appears at the leaf axils, and they are usually produced between mid-summer and autumn.
Tank Size
Because Ludwigia palustris is a medium-sized plant, it can be grown in relatively small fish tanks. A 10-gallon tank or larger should be plenty big enough to host these plants, and they can always be pruned back to keep them at a suitable size.
In smaller tanks, they make a good background plant, but in larger, heavily planted tanks they might look better in the mid-ground, or even kept pruned low and grown in the foreground.
Water Parameters
Ludwigia palustris is a fairly hardy plant and should be tolerant of a wide range of water parameters. Most guides recommend water with a pH of 6-8, but you could probably grow this plant in slightly more acid or alkaline water, too.
Water hardness from 2-30 dGH should be fine.
Substrate
Ludwigia palustris isn’t particularly fussy when it comes to substrates, but I’ve heard reports of Ludwigia plants struggling to grow in sandy substrates. Aquarium sand can get so compacted that oxygen levels become depleted, making it difficult for roots to grow.
Gravels can provide solid, aerated anchorage for your plants but are lower in nutrients. Fertilizers in root tabs may be necessary if you plan on growing lots of plants in your gravel.
if you want to go for the heavily planted aquarium, the best substrate is aquarium soil. Good aquarium soil is specially formulated to contain a balanced blend of nutrients your plant needs to thrive.
A plant that’s given adequate nutrients in a good substrate will be more vigorous, with lusher colors and shiny, dark, healthy-looking leaves.
Ludwigia palustris Lighting
Ludwigia palustris can grow under moderate lighting but will tend to display its fullest red colors when grown under stronger lighting. Strong lighting is especially important if you decide to boost the tank with extra CO2.
For the brightest colors, choose LED or fluorescent bulbs with higher PAR values. It will help the plant grow vigorously, display more intense colors, and form an attractive bushy shape rather than long, thin stems.
I’d recommend keeping the lights on a timer switch for 10-12 hours a day.
Does Ludwigia palustris Need Fertilizer?
Ludwigia palustris requires reasonable nutrient sources to grow vigorously but should grow moderately well in most fish tanks without fertilizers. My advice would be to plant them and see how they grow in your tank without fertilizers and only add fertilizer later if your plants are struggling.
If it’s growing in good aquarium soil, there should be adequate nutrient levels for the plant to grow for several years without supplements. Otherwise, you could add root tabs or liquid-based aquarium plant feeds to supplement their growth if necessary.
Just be careful not to use a fertilizer that contains nitrates without testing your water first. The maximum nitrate level for most fish is 20 ppm, which is more than enough for most aquarium plants, too.
Also, a note of caution about plant foods that contain copper! Even small amounts of copper are highly toxic to invertebrates like shrimp and snails. If you have invertebrates in your tank, be sure to choose a fertilizer without added copper compounds!
Does Ludwigia palustris Need CO2 Injection?
All plants need carbon dioxide to photosynthesize, and some aquatic plant enthusiasts use CO2 injectors to increase the dissolved CO2 in their aquariums to boost their plants’ growth rates and all round vigor.
Ludwigia palustris only grows at a modest rate and doesn’t tend to be especially hungry for CO2, but if you’re using higher levels of lighting, then additional CO2 can help Ludwigia to grow faster.
As with fertilizers, it depends greatly on your particular tank and its inhabitants. Respiration in fish and microorganisms in your aquarium may already be producing enough CO2 for your plants to absorb.
If you really want your aquascape to glow with masses of luxuriant plant growth, however, then increased lighting and CO2 injection will give you the edge.
Just make sure not to overdo it, as CO2 levels above 32 ppm can be dangerous to your fish and other aquarium pets.
Ludwigia palustris Pruning
If you give Ludwigia palustris the ideal conditions, it will eventually grow to a fairly large size. If it begins to crowd out other plants or look scruffy, you’ll need to prune it back.
Pruning typically consists of cutting the top few inches from the tops of the stems. Not only does this control the plant’s size, but it also encourages attractive, compact, bushy growth.
When pruned back hard, Ludwigias can also be utilized as shorter midground plants rather than taller background plants.
Ludwigia palustris Propagation
Propagating aquatic stem plants goes hand in hand with pruning. Simply snip off 4-8 inch long stems and place the bottom of the stem in the substrate, at least 2 inches deep.
Stems should soon grow roots and shoots, and begin growing away within a week or two.
For faster growth, you could use a specially dedicated tank to give cuttings optimal levels of light and nutrients.
Propagating by placing cuttings in pots in a mist unit or humid tank with moist substrate is a method sometimes used by professionals.
Companion Plants and Aquascaping
The red foliage of Ludwigia palustris looks beautiful alongside aquarium plants with green leaves. It can be placed in the background, midground, or foreground of the aquarium, depending on the size of the tank, and how regularly you prune it.
It can be planted in the background of an aquascaped aquarium alongside tall green plants like Amazon sword, Limnophila Sessiliflora, Blue Water Hyssop, Hornwort (Ceratophyllum demersum), and Brazilian Pennywort (Hydrocotyle leucocephala).
In the mid-ground, you could plant it alongside medium-sized plants like Corkscrew Vallisneria (Vallisneria torta) and Java Fern (Leptochilus pteropus).
In the foreground, the smallest aquarium plants like Dwarf hair grass (Eleocharis parvula), Anubias nana, and Java moss will be the most suitable.
Compatible Fish and Invertebrates
Ludwigia palustris will grow fine alongside any tropical aquarium fish, shrimp, and snails that don’t eat healthy aquarium plants!
Most fish and invertebrate species will be fine, but not notorious plant eaters like Goldfish, Silver Dollars, Oscars, or Columbian Ramshorn Snails.
Some people have also had problems with the Apple Snail family (including the usually well-behaved mystery snails) eating their plants, especially if other food sources are scarce.
Note that snails are more likely to nibble at plants that are struggling or have ‘melting leaves’ than those that are radiant with health.
Ludwigia palustris Selected Cultivars
As with other Ludwigia species, plant breeders have been selecting plants with the brightest red pigments to breed from. One popular variety with a particularly strong color has been branded ‘Super Red’ and is sometimes sold as ‘Ludwigia natans Super Red’ – owing to the confusion about the species distinction.
Even though there is also another plant known as ‘Ludwigia Super Red Mini’, it’s thought to be simply smaller plants of the same cultivar, rather than a unique variety.
It’s important to note that vivid red colors on any variety of this plant will only reach their full potential when given adequate lighting.
Ludwigia palustris Buyer’s Guide
Because it’s an easy and fairly popular aquarium plant to grow, Ludwigia palustris is fairly easy to find in pet stores and online plant outlets.
Remember that there’s much confusion, even among experts, about the different species, but Ludwigia natans is so similar (if not a variation of the same species) that the two species are interchangeable for practical purposes.
Only buy healthy plants that are growing vigorously, with vibrant, glossy leaves. Make sure there are no parasites or unwanted snail species attached to the leaves, and consider trialing the plants in a quarantine tank before adding them to your main tank.
You can expect to pay between $5-$15 for a well-formed plant.
Can You Grow Ludwigia palustris Out of Water?
Ludwigia palustris will grow well when emersed (grown out of water), so long as the substrate is kept moist.
The extra light and CO2 available out of water can help emersed plants grow rapidly, leading some aquarium plant breeders to choose this method above growing plants underwater.
Because it’s possible to grow Ludwigia palustris out of the water, it also does well growing in suitable terrariums, paludariums, and vivariums.
Can You Grow Ludwigia palustris in a Cold Water Aquarium?
Since Ludwigia palustris is native to the Northern United States, it should be able to grow in an aquarium without a heater.
Having said that, the extra warmth provided in a tropical fish tank may help plants to grow more vigorously than in a coldwater fish tank.
Conclusion
Ludwigia palustris is an easy-to-grow red-stemmed plant for beginners and advanced aquarists alike. Its beautiful red colors can provide a stunning contrast to any green foliage plants surrounding it, making it a long-term mainstay in the aquarium trade.
Remember, however, that there is much confusion between the different Ludwigia species, even within the scientific community. Ludwigia natans is so alike that the two plants are interchangeable, and Ludwigia repens is a very similar, popular red-stemmed plant, too.
