How to Care For Water Wisteria (Hygrophila diformis)

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). Learn our top tips and tricks to plant your new wisteria and get past the melting phase. Then, propagate 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. It will however, let you know if there is not enough lighting or fertilizer by melting when it becomes starved.

Why doesn’t my new water wisteria look like the photos online?

Wisteria is a live aquatic plant that is commonly grown in commercial plants farms. The leaves and stems are taken out of the water, and the roots are kept in the water. This is an efficient way to grow plants faster, larger, and without pests and algae. Emersed plants are plants grown above water surface. They have thicker stems, which can withstand gravity, and wider leaves that can absorb carbon from the atmosphere. Wisteria produces emersed leaves that look like strawberry leaves – featuring a roughly 1.5-inch (4 cm) oval shape, grooved veins, and slightly jagged edges.

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 tend to be thinner, more delicate and narrower than emersed growth. 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.

Submersed-grown wisteria leaves (on the right)

What’s the difference between water-wisteria (Ceratopteris Thalictroides), and water-sprite? While both have delicate, lacy leaves, water sprite’s leaves are more needle-like and thinner. 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. Take out the stems from your rubber band and wrap the bundle or rock wool in a plastic pot. 2. Trim any stems or leaves that were damaged during transportation. 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. Wisteria can also grown floating, where it rises to the surface of the water and grows lots of hanging root along its horizontal stem.

Planting water-wisteria in gravel using tweezers

Why is My New Wisteria Plant Dying?

The wisteria will look great for the first few days after it is planted. Then halfway through the first week, emersed leaves will start turning yellow and then brown, especially near the bottom of the stems. If the leaves turn brown, you can take them out to prevent your aquarium from absorbing rotting organics. If your wisteria is lacking in light and/or nutrients, the stems may turn brown and melt away. Replant the green, healthy parts of the wisteria by removing the soggy stems. As needed, add additional lighting and fertilizer.

Emersed-grown leaves at the base of the stem tend to brown and melt off first.

How to Convert 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. For a low tech tank with dimmer lighting and no CO2 injection, it may take about a month for the first submersed leaves to appear. You can speed up the process by using medium to high lighting in your aquarium. The wisteria should be placed directly under the sunlight. You can also add nutrients to the water column with an all-in one liquid fertilizer. If you have soft water that has low levels of GH, you may need to supplement it with a mineral supplement. While CO2 injection does not need to be done, it can reduce conversion times as it provides more building blocks for the Wisteria.

Plant the wisteria in a substrate and don’t move it. 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. After they have grown enough roots to be able to plant in the substrate, you can replant them. Keep the water parameters, lighting, fertilizer, and water quality stable as wisteria can easily melt in volatile environments.

At Aquarium Co-Op we try to source submerged-grown wisteria in order to jumpstart the conversion and save you the hassle.

How to Propagate water wisteria

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. You can remove the top half of the stems so that it doesn’t block the light or outcompete other plants. The bottom half of the stem can be left in the ground and will eventually produce new leaves. 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. Once several inches of submerged leaves have grown, you can trim off the healthy tips and plant them again to replace the emersed-grown portions.