How to Care for Water Wisteria (Hygrophila Difformis)

How to Care for Water Wisteria. (Hygrophila.difformis).

Water wisteria (Hygrophila difformis) is a very popular aquarium plant in the hobby because of its lacy leaves, bright green color, and rapid growth. While its care requirements are easy, this species is very prone to melting and losing its leaves when you first purchase it (similar to melting Cryptocoryne plants). Find out our best tips and tricks for planting your new wisteria, getting past the melting phase, and propagating it to grow new plants.


What is Water Wisteria?

This aquatic stem plant is native in India and Thailand. It can reach heights of up to 20 inches (51cm) and widths of 10 inches (25cm). (At greater heights, light has difficulty reaching the base of the wisteria and thus the bottom leaves may begin to thin out.) Many people use this bushy species as a background plant in their fish tanks, but you can also plant it in the foreground or midground if you want to cut it shorter. As a fast-growing plant, it is often used to consume nitrogen waste compounds in the water and outcompete algae growth. If you don’t provide enough light or liquid fertilizer, the plant will tell you by melting away from starvation.

Why is my new water not looking like the pictures?

Like many live aquatic plants, wisteria is often grown in commercial plant farms with its leaves and stems out of water and roots in the water. This is an efficient way to grow plants faster, larger, and without pests and algae. Emersed-grown plants (or plants grown above the water surface) generally have thicker stems that are built to withstand gravity and broader leaves that can absorb carbon dioxide directly from the air. Wisteria produces emersed foliage that looks like strawberry leaves. It has a oval shape of approximately 1.5 inches (4 cm) and grooved veins. The edges are slightly jagged.

Wisteria leaves emersed-grown

Once you place the wisteria in your fish tank, it must drop its old, emersed leaves and grow new, submersed leaves (or leaves that are grown completely underwater) that are capable of drawing carbon dioxide and other nutrients from the water. Submerged leaves look thinner, smaller, and more delicate than their emersed counterparts. Submerged leaves of Wisteria can look very different to their emersed counterparts. This can cause confusion. However, they are the same species that adapts to changing environments and changes their leaf appearance. Wisteria can grow underwater to produce bright green, feathery, and tall fronds measuring 4 inches (10 cm). Its bushy appearance can be used to add an interesting visual texture to planted tanks and is perfect for hiding fish fry or shrimp.

Submerged-grown wisteria leaves (on right)

What are the differences between water wisteria, water, and water, sprite, and how do they look? Wisteria and water, both Ceratopteris.thalictroides, have delicate, lacy, similar leaves. However, when compared side by side, water, sprite has more needle-like, thinner leaves. Water wisteria can grow long stems, while water sprite creates new shoots at its base.

Submersed-grown water sprite

How to Plant Water Wisteria

1. Carefully remove the stems from the rubber band, bundle, or rock wool inside the plastic pot. 2. Any stems or leaves damaged in transportation should be cut. 3. Use your fingers or tweezers to push the stem’s base into the substrate or gravel as deep as you can. 4. Plant each stem separately approximately 1-2 inches (2.5-5 cm) apart so they have room to develop roots and become anchored.

If you have fish that like to dig in the substrate, protect the newly planted stems by surrounding the patch of wisteria with a ring of rocks, wood, or other decorations. Alternatively, wisteria can also be grown as a floating plant where it simply rises to the water surface and develops lots of hanging roots all along the horizontal stem.

Planting water with tweezers in gravel

Why is My New Wisteria Plant Dying?

After you plant the wisteria, expect it to look good for the first couple of days. After the first week, the emersed leaves will begin to turn yellow, and then brown, particularly near the bottom of their stems. If the leaves turn brown, you can take them out to prevent your aquarium from absorbing rotting organics. The stems of wisteria that isn’t getting enough light or nutrients may become brown and eventually melt. Cut off the brown, soggy stems and replant the healthy green parts of the wisteria. Then add more lighting or fertilizer as needed.

Emersed leaves at the base a stem tend to turn brown and then melt off.

How to Convert Your Wisteria from Emersed to Submersed Growth

The conversion phase can take anywhere from a couple of weeks to a couple of months, depending on the fish tank’s light, nutrient, and carbon dioxide (CO2) levels. A low-tech tank may require a month to see the first submerged leaves. For faster results, you can use moderate to high lighting. Place the wisteria directly in front of the sun and ensure that other plants do not shade it. Make sure to add lots of nutrients to the water column by using an all in one liquid fertilizer. You may also need to add a mineral supplement if your water has low levels of GH. Although CO2 injection is not necessary, it will significantly reduce the conversion time as it provides more building blocks that the wisteria can use.

It is best to keep the wisteria planted in the substrate intact. You can stop the ground from growing if it is disturbed. It will then adjust to the new environment and continue to grow for a while. Make sure that your stems don’t grow out of water too much. They may develop more emersed than submerged leaves. If you are having trouble getting your wisteria to convert, try floating some stems where they can collect more light and CO2 at the water surface. Once they start growing a decent amount of roots, then you can try planting them in the substrate again. You should also keep your water parameters, lighting, as well as fertilizer stable. Wisteria is prone to melting if its environment becomes volatile.

At Aquarium Co-Op our goal is to source submerged-grown Wisteria to speed up the conversion process and to save you the trouble.

How to Propagate Water Wiseria

Once the plant becomes well-established, it can start growing like a weed at a rate of 0.5-3 inches (1-8 cm) per day. To prevent it from blocking all the light and outcompeting other plants, cut off the top half of the stems and replant the trimmings to propagate the wisteria. You can leave the bottom half of the stem in the ground, and it will eventually grow new leaves from the tip. However, if the bottom half is too “leggy” and lost most of its leaves during conversion or from lack of light, many people choose to remove it and plant the top half of the stem in its place. You should not allow the wisteria to cover more than half of the water surface. It can shade other plants and make the water stagnant.

Lower-growing emersed leaf sections have developed holes, and algae growth. The new, submerged leaves at stem tips are healthy, bright green, and the stems remain intact. When several inches of submersed leaves have grown, you can cut off the healthy tips and replant them to replace the old, emersed-grown sections.