Propagating Aponogeton undulatus (Wavy-Leaf Aponogeton)

How to propagate Aponogeton undulatus by adventitious plantlets that form on the flower spike, plus tuber division and seed, with care notes for the aquarium.

Overview

Aponogeton undulatus, the wavy-leaf aponogeton, is a submerged aquatic of the family Aponogetonaceae native to India, Bangladesh, Myanmar and Sri Lanka. It grows from an ovoid tuber roughly 2 inches long and bears pale green leaves 4-6 inches long with characteristically undulating margins on slender petioles. It is a popular, reliable specimen plant that tolerates varied water and lighting and is a root feeder.

Propagation Method

The primary method is harvesting the adventitious plantlets that develop on the inflorescence stalk: each forms its own tuber and can be detached and planted. The tuber itself can also be divided, and the species can be raised from seed via hand-pollination, although true flowering is rare. For most aquarists, the plantlets are the easiest and most prolific route.

Step-by-Step

Let the plant push up a spike; instead of flowers, plantlets will form along it.
Allow each plantlet to develop its own leaves, roots and small tuber on the spike.
Detach mature plantlets once they have roots, or break them off slightly early, and plant them straight into the substrate.
Alternatively divide a large tuber, or hand-pollinate any true flowers and germinate the seed in fine substrate under shallow water.

Conditions for Healthy Growth

Moderate light; it prefers bright positions but tolerates partial shade.
Warm tropical water around 22-28 C with a wide tolerance of conditions.
Nutrient-rich substrate, since it is a root feeder.
No CO2 is required for reliable growth.

Maintenance

The true species rarely (if ever) enters a rest phase, so it generally grows year-round, though some plants slow at lower temperatures. Feed through the root zone, keep the plantlet-bearing spikes intact until the young plants are ready, and remove old or damaged leaves as needed. Bury only the lower part of the tuber so the crown stays exposed.

Common Challenges

Expecting seed from flowers: the plant almost never flowers, propagating instead by plantlets on the spike.
Detaching plantlets too early before they have roots, which lowers their survival.
Confusing it with hybrids, some of which produce floating leaves while the true species does not.
Weak root nutrition, since it relies on the substrate as a root feeder.