Water wisteria

Overview

Water wisteria (Hygrophila difformis) is one of the best plants for beginners. Submersed, it grows sturdy stems with deeply lobed, light green leaves that look almost fern-like, while out of water or in low light it produces broader, rounder leaves. That variability is where its scientific name comes from: "difformis" means differently shaped.

It is native to South and Southeast Asia (India, Thailand, Malaysia), where it grows in marshy areas. Hobbyists like it because it grows very fast without CO2, fills in the background within weeks and soaks up nitrate and phosphate, outcompeting algae. It is perfect for new tanks, beginners and breeding tanks where fry need cover. Its only downside is that, left untrimmed, it will take over the aquarium.

Care and tank setup

Plant it in the background or along the sides; it quickly outgrows small tanks, so it fits best in 15 gallons (57 liters) and up.

• Light: medium. It still grows in low light, but with less lobed, more widely spaced leaves.
• CO2: optional; it grows very well without it.
• Substrate: any gravel or sand; root tabs help keep the green vivid.
• Planting: single stems about 1.5 inches apart, with leaves stripped from the buried section; it can also float for a while.

Its large leaves shade whatever grows beneath, so do not plant it in front of light-hungry plants. Some herbivores, such as silver dollars and certain cichlids, will happily eat it. Left floating, it grows hanging roots without any trouble.

Fertilizing and trimming

Because it grows so fast, it is a heavy feeder: a weekly comprehensive liquid fertilizer prevents yellow leaves (nitrogen deficiency) or pinholes (potassium deficiency). Trim often, cutting the tops when they reach the surface and replanting them; if you only cut from the top, the base branches out and gets very dense. Remove old stems so decaying material does not build up.

Propagation

It propagates extremely easily from top cuttings, which root within days. On top of that, loose leaves left floating can grow roots and new plantlets. So when you trim, collect every piece. It is a vigorous grower, so never dump extras into streams, lakes or drains: put them in the trash or compost.

Recommended equipment

What you need to keep the Water wisteria healthy, checked against Amazon stock.