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). The wisteria’s base may become less visible due to the increased height. As a result, the leaves can begin to thin. 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. This fast-growing plant is known to be a good eater of nitrogen waste compounds and can outcompete algal 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?
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-grown plants, or plants that have been grown above the water surface, generally have thicker stems and larger leaves that can absorb carbon dioxide from the air. 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. Submersed leaves are usually thinner, narrower, and more delicate in appearance. 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 left)
What is the difference between water wisteria and water sprite? Both wisteria and water sprite (Ceratopteris thalictroides) have delicate, lacy leaves that look quite similar, but when compared side to side, water sprite has thinner, more needle-like 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. Remove the stems of the rubber band and bundle the rock wool. 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. Each stem should be planted separately, approximately 2 to 3 inches (22.5-5 cm) apart, so that they can 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. You can also grow wisteria as a floating plant. It simply rises to surface water and forms lots of hanging roots along its horizontal stem.
Planting water wisteria in the gravel with tweezers
Why is my New Wisteria Plant Dying
After you plant the wisteria, expect it to look good for the first couple of days. Then halfway through the first week, emersed leaves will start turning yellow and then brown, especially near the bottom of the stems. Once the leaves are brown, you can remove the leaves if you wish to avoid having excess rotting organics in your aquarium. 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. Add more fertilizer or lighting as necessary.
Emersed-grown stem leaves at the base tend to brown first.
How to convert your Wisteria from emersed to submerged 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. Also, provide lots of nutrients in the water column using an all-in-one liquid fertilizer, and add a mineral supplement if you have soft water with low amounts of GH. CO2 injection is not required but will greatly shorten the conversion time since it provides more building blocks for the wisteria to use.
If you plant the wisteria in the substrate, try not to move it around. 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. You should also ensure that the stems do not grow too high or out of the water. Otherwise, they might develop more emersed foliage instead of submerged leaves. Try floating stems in the water to increase light and CO2 absorption. After they have grown enough roots to be able to plant in the substrate, you can replant them. 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, we strive to source submersed-grown wisteria to jump start the conversion process and save you the hassle.
How to Propagate water wisteria
Once established, the plant can grow like a weed at a rate between 0.5-3 inches (1-8cm) per day. You can remove the top half of the stems so that it doesn’t block the light or outcompete other plants. The stem’s bottom half can be left in place and it will eventually sprout 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. If the wisteria has begun floating, it should not cover more that 50% of the water surface. This will cause it to shade other plants, and lead to stagnant, oxygen-deprived waters.
The emersed lower leaves have developed holes and growth of algae, while the new submerged leaves at the tips are bright and healthy. 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.