Propagating Alternanthera reineckii 'Rosaefolia'

How to propagate the broad-leaved red cultivar Alternanthera reineckii 'Rosaefolia' from stem cuttings, with the light, CO2 and trimming it needs for rich pink-red color.

Overview

Alternanthera reineckii is native to South America, where it grows in submerged and semi-aquatic habitats such as marshes, stream banks and ponds. 'Rosaefolia' is one of several broad-leaved cultivars used as an ornamental in aquaria, prized for the pink-red coloration of its leaves that intensifies under strong light. As a cultivar it does not come true from seed in the aquarium, so it is multiplied vegetatively from stem cuttings, with every cutting carrying the same color and broad-leaf form as the parent.

Propagation Method

The reliable method is stem cuttings, also called topping. You cut the top 5-10 cm of a healthy shoot, strip the lowest leaves, and replant it in the substrate beside the parent group. Removing the terminal bud this way also pushes the mother plant to throw new side shoots from below the cut, so the original stem grows bushier and gives you more cuttings over time.

Step-by-Step

Choose a strong, well-colored stem at least 12-15 cm tall.
Cut the top 5-10 cm just above a leaf node with clean scissors.
Strip the leaves from the lowest 2-3 cm of the cutting.
Push the bare stem 2-3 cm into the substrate, planting cuttings in a group for a fuller look.
Leave the trimmed parent in place so new side shoots emerge below the cut.

Conditions for Healthy Growth

Good light strongly favors this plant: under strong illumination the leaves turn the deepest red, while weaker light leaves them paler. Added CO2 (a medium demand of roughly 6-14 mg/L) improves growth and overall appearance. Plant in nutrient-rich substrate and keep iron and other micronutrients available, since the red broad-leaved cultivars are high feeders. Cuttings root within a couple of weeks and resume vertical growth toward 20-30+ cm.

Trimming & Maintenance

Trim regularly and lightly rather than all at once. Cut the longest shoots right above a bottom leaf and replant the tops in the group; new shoots emerge from the trimmed stem, so repeated trimming yields a denser stand. A roughly two-week trim cadence keeps the planting compact and the lower leaves lit.

Common Challenges

Weak or yellowing lower leaves usually mean too little light, CO2 or nutrients; raise these before expecting strong red color. Cuttings that float free have too little stem buried or too few leaves stripped, so anchor them deeper. Avoid topping all stems at once, which strips the planting of color while it regrows.