Didiplis diandra

Didiplis diandra is a semi-aquatic plant native to the freshwater wetlands, shallow streams, and boggy margins of the eastern United States. In its natural habitat it grows partially emersed in nutrient-rich, slightly acidic soils and shallow water, forming low-growing mats with inconspicuous flowers. Submerged, it develops a dramatically different appearance with densely packed, linear leaves that give stems a fine-textured, almost bristle-like quality. The plant's capacity for intense orange-to-red colouration in the upper portions of stems under strong light and CO2-enriched water makes it a sought-after accent plant in competitive aquascaping. This colour transformation is driven primarily by anthocyanin production in response to high light and iron availability. In the aquarium it is best suited to the midground or background of high-tech setups and should be planted in groups for maximum visual impact. Didiplis diandra is sensitive to sudden water parameter changes and dislikes hard or alkaline water, which limits its accessibility to experienced hobbyists who can maintain stable conditions.

Placement Best planted in the midground or background in groups of 6–10 stems to showcase its colour gradient. Avoid placing it near aggressive filter flow that may damage delicate leaves.

Lighting Requires high lighting (60–100 PAR) to achieve red-orange colouration. Under lower light, stems remain green and etiolate. Run a photoperiod of 8–10 hours with high-output LED or T5 fixtures.

CO2 & Fertilisation CO2 injection is essential, targeting 25–35 ppm. Comprehensive macro- and micronutrient dosing including iron (0.1–0.5 ppm Fe) is critical for colour development. EI or PPS-Pro dosing methods work well.

Propagation Trim tops at 8–10 cm and replant directly into substrate. The plant produces lateral shoots readily after trimming. Roots establish within 10–14 days in warm, soft water.

Trimming Trim every 2–3 weeks once stems reach midtank height. The most colourful portions are the upper tips; replanting these ensures the best display. Remove lower sections that have become bare or woody.