Marble Queen Radican Sword (Echinodorus cordifolius)

The Marble Queen Radican Sword (Echinodorus cordifolius 'Marble Queen') is a bold, easy-care centerpiece plant with broad, heart-shaped leaves splashed in creamy marbled variegation. It grows into a large, dramatic specimen that anchors the midground or background of a tank, and it is forgiving enough for beginners while still rewarding planted-tank enthusiasts. Explore our full freshwater aquarium plants collection to build out the rest of your aquascape.

Care Guide

Like most sword plants, the Marble Queen is a heavy root feeder. It does best planted in a nutrient-rich substrate or with root tabs tucked under the crown, where its strong root system can pull up the food it needs to push out big, well-marbled leaves. Plant it with the crown (where leaves meet roots) just above the substrate so it does not rot. It is a slow-to-moderate grower that, once established, fills out into a lush rosette.

• Lighting: Moderate to high. Brighter light keeps the variegation crisp and the plant compact; 10 to 12 hours a day works well.
• Feeding: Heavy root feeder. Use root tabs in inert gravel or sand. Pale or yellow leaves usually mean it wants more iron.
• CO2: Not required, but supplemental CO2 produces faster, fuller growth in high-light tanks.
• Size: A large plant. Submersed it commonly reaches 12 to 16 inches and can grow taller, so give it room and a tank of 20 gallons or more.
• Bonus: Grown emersed in a paludarium or open tank it can send up tall flower stalks that produce baby plantlets you can replant.

Specifications

In the Aquarium

The Marble Queen earns its keep as a single statement plant in a community tank, planted slightly off-center so its variegated leaves draw the eye. It pairs beautifully with darker green companions like crypts and other swords, and the broad leaves give shy fish a sense of cover. Because it gets large, leave space around it so the outer leaves can spread without crowding smaller foreground plants.

Recommended Pairings

• Seachem Flourish Tabs tucked under the roots, this sword is a heavy root feeder and grows best with them.
• An iron supplement to keep the marbled leaves bright and prevent yellowing.
• Companion rooted plants: Amazon Sword, Melon Sword, and Cryptocoryne wendtii 'Bronze'.

FAQ

How big does it get?
It is a large sword. Expect 12 to 16 inches or more when established, so it is best suited to tanks of 20 gallons and up where it has room to spread.

Do I need CO2 to grow it?
No. It grows fine without CO2 in moderate light. CO2 and stronger light simply speed up growth and produce larger leaves.

My new leaves are pale. What is wrong?
Pale or washed-out leaves on a sword usually point to a lack of iron or root nutrients. Add root tabs and an iron supplement and the marbling will firm up.

Why are some leaves melting after I planted it?
Swords often drop a few older leaves while adjusting to a new tank, especially if they were grown emersed at the farm. Trim the melted leaves; new submersed growth will follow.