Soil & potting mix
Best soil for Ivy-leaved Duckweed (Lemna trisulca)
Also called Ivy-leaved Duckweed, Star Duckweed.
More about ivy-leaved duckweed
About Ivy-leaved Duckweed
Lemna trisulca · also called Ivy-leaved Duckweed, Star Duckweed · flowering
Ivy-leaved Duckweed is a distinctive submerged duckweed native to Europe, Asia, and North America, forming translucent pale-green fronds connected in branching chains beneath the water surface. Unlike other duckweeds, it stays submerged until flowering. An excellent oxygenator and fish food plant for wildlife ponds and aquaria. Hardy and low-maintenance.
Preferred mix: Free-floating — no substrate required
Why ivy-leaved duckweed needs this mix
Ivy-leaved Duckweed grows on air — it has almost no functional root system for feeding, so it is never planted in soil at all.
- Ivy-leaved Duckweed absorbs moisture and nutrients through specialised scales on its leaves, so a pot of soil does nothing useful and only traps damaging moisture against its base.
- Its few roots exist mainly to anchor it to bark or rock — they are not feeding roots and rot quickly if buried.
- Free air movement is essential: it must dry within a few hours of every watering or the centre rots.
For the full picture on what makes up a good mix, see our guide to the main types of soil and potting media — it explains why each ingredient above behaves the way it does.
What goes wrong with the wrong mix
The wrong soil is one of the most common reasons ivy-leaved duckweed struggles, and the damage often shows up weeks later as a watering problem. For this species specifically:
- Potting ivy-leaved duckweed in soil or packing moss around its base is the classic killer — the crown stays wet and goes black and mushy from the inside.
- Sitting it in a closed terrarium or sealed glass globe with no airflow has the same effect more slowly.
- Glued-onto-a-shell ornaments trap water under the base and rot it; if you have one, prise it off.
Planting ivy-leaved duckweed in any kind of soil or substrate, or displaying it somewhere it cannot dry out within hours of watering.
pH — does it matter for ivy-leaved duckweed?
pH is irrelevant for ivy-leaved duckweed — there is no soil. What matters is water quality: use rain or filtered water, as it is sensitive to tap-water minerals.
If you want to check or adjust it, the soil pH guide walks through testing and the safe ways to nudge a mix more acidic or more alkaline.
DIY mix vs a bagged one
There is no mix to buy or make for ivy-leaved duckweed. "DIY vs bagged" does not apply — instead invest in a mount, wire or fishing line and a bright, airy spot.
Drainage and the pot
Drainage means airflow here: after soaking or misting, turn ivy-leaved duckweed upside down to shed water from its centre and let it dry fully before returning it to its display.
There is nothing to repot. Simply re-mount ivy-leaved duckweed if it outgrows its slab, and never wrap its base in moss that stays wet. When the time comes, our repotting guide for ivy-leaved duckweed covers the timing and technique step by step.
Ivy-leaved Duckweed soil — frequently asked questions
What is the best soil mix for ivy-leaved duckweed?
No soil — display bare, in an open vessel, or wired to a mount or slab. Ivy-leaved Duckweed absorbs moisture and nutrients through specialised scales on its leaves, so a pot of soil does nothing useful and only traps damaging moisture against its base.
Can I use normal potting soil for ivy-leaved duckweed?
Potting ivy-leaved duckweed in soil or packing moss around its base is the classic killer — the crown stays wet and goes black and mushy from the inside. There is no mix to buy or make for ivy-leaved duckweed. "DIY vs bagged" does not apply — instead invest in a mount, wire or fishing line and a bright, airy spot.
Does ivy-leaved duckweed need a special pH?
pH is irrelevant for ivy-leaved duckweed — there is no soil. What matters is water quality: use rain or filtered water, as it is sensitive to tap-water minerals.
Should I buy a bagged mix or make my own for ivy-leaved duckweed?
There is no mix to buy or make for ivy-leaved duckweed. "DIY vs bagged" does not apply — instead invest in a mount, wire or fishing line and a bright, airy spot.
How often should I refresh the soil for ivy-leaved duckweed?
There is nothing to repot. Simply re-mount ivy-leaved duckweed if it outgrows its slab, and never wrap its base in moss that stays wet. Drainage means airflow here: after soaking or misting, turn ivy-leaved duckweed upside down to shed water from its centre and let it dry fully before returning it to its display.
Keep reading
- Ivy-leaved Duckweed care — the full brief (light, water, humidity, problems, pet safety)
- How often to water ivy-leaved duckweed — the schedule the mix feeds into
- Repotting ivy-leaved duckweed — when and how to refresh the mix
- Soil pH guide — test it and adjust it safely
- Overwatered plant — signs and recovery
- Root rot — how the wrong soil starts it, and how to save the plant
- Why is my plant wilting? Wet vs dry diagnosis
- Best soil for starflower
- Best soil for large-flowered bellwort
- Best soil for sessile bellwort
- All 8452 soil and potting-mix guides in the Growli library