To be truthful, I am more of an outdoor plant person than a houseplant person. But my partner loves tropical houseplants and he’s always adding to our collection (we have over 100 now). He loves to propagate cuttings from friends and is prone to rescuing dying houseplants in the sale section of the big box home improvement store. Unfortunately, some of those rescue plants don’t fare much better once they’ve made it home.
A few months ago, one of my good friends from the park service mentioned that she has had great success switching some of her pickier tropicals from traditional soil to LECA, which is a type of semi-hydroponic medium. LECA stands for “lightweight expanded clay aggregate” and can be beneficial for certain houseplants.
Using LECA takes a little getting used to and it is not a suitable medium for all houseplants, but the plants I switched to LECA are making a great recovery.
What is LECA?
Lightweight expanded clay aggregate (LECA) is a soilless growing medium that looks like clay marbles. LECA balls are made by heating natural clay to high temperatures in a rotating kiln. This causes the clay balls to expand and become porous. LECA balls are great at wicking water while also providing lots of air circulation for plant roots.
LECA is lightweight, pH neutral, and reusable. Although it is on the pricier side of soilless media, it can be a great option for plants that are easily damaged by soggy soil. Unlike traditional potting soil, LECA clay balls won’t harbor any pests like fungus gnats. I also love that it is less messy than potting soil.
You can purchase LECA balls at Amazon, the Home Depot, or from your local garden center.
Which Plants Benefit From LECA?
Plants like monstera, alocasia, orchids, snake plants, and philodendrons all do well in LECA. I switched a ‘Thai Constellation’ variegated monstera and two alocasia plants from soil to LECA and they have been recovering well and putting out new growth like crazy.
These plants had root rot problems in the potting soil they came in from the big box store and I was afraid they were a lost cause. Making the switch to clay balls was a Hail Mary effort and it has paid off!
Other plants that do well in LECA include ZZ plants, spider plants, jade plants, peperomia, and hoya.
How to Make the Switch to LECA
Using LECA as a soilless medium does require investment of time and practice in order to get it right. Here is how to get started:
- Rinse the clay balls to remove any excess clay dust. Rinse repeatedly until the water runs clear.
- Soak LECA balls in water for 24-48 hours so they absorb water and will be ready to transfer the water to your plant’s roots.
- Remove the plant from its pot and gently rinse all the soil from the roots. This takes time and patience. All soil needs to be completely removed so that the water in the new semi-hydroponic set up doesn’t get mucky. This is also a good time to trim any mushy or diseased roots.
- Place the first layer of LECA balls in your container of choice and gently place your plant’s roots on top. While holding the plant, gently fill clay balls around its roots until you reach just below the base of the stalk. Add more clay balls if necessary to ensure the plant is stable, but do not have the balls touching the stalk.
- Use filtered water to fill up the bottom third of your container, or just to where the root tips are. As the plant adjusts, it will grow new roots that are adapted to the level of moisture.
- Be patient and monitor closely. The transition period to LECA is different for each plant, so keep a close eye on it and make changes as necessary.
More Tips for LECA
- Since LECA is a completely inert material, there are no nutrients and you will need to use hydroponics fertilizer like this FloraGro trio from General Hydroponics, which is available from Amazon.
- Younger plants with less complex root structures are easier to transplant into LECA and will make the transition better than older plants.
- Since using LECA requires some experimentation, try it out with a small plant that you don’t have much investment in. A great way to start is by taking a cutting from a healthy plant, get roots started in a propagation station, and then transfer it to a LECA setup.
