LECA is rapidly becoming one of the most popular alternatives to conventional growing mediums, and for good reason. It’s sterile, pH neutral, and doesn’t break down over time, meaning that once you have it, you have it forever.
As we’ve described in detail in LECA: Going Semi-Hydro, LECA is a superheated clay aggregate with unique capillary properties, which draw water up to your plant’s roots without compacting and starving them of oxygen. This allows you to precisely meet your plant’s nutrient needs, extending life expectancy and increasing growth rate, while also providing us a special look at what those little roots are up to. There are lots of reasons why you’d consider making the change to LECA—from the space restrictions of a small apartment or wanting to be on the cutting edge of the amateur horticulture world—but today we’re going to focus on the step-by-step of how to make the transition.
Two Styles of LECA
The main method that we’ll be looking at today is referred to as the Inner/Outer method and involves two containers: one plastic container with drainage holes to hold your plant, and an outer container without drainage holes to hold your nutrient reservoir.
This allows you to easily lift your plant and LECA out of the nutrient reservoir, giving you room to adjust, test pH, or flush out salt or plant waste that may collect over time.
The other method relies on a transparent glass or plastic container, in which you will place your LECA, your plant, and your nutrient reservoir. This way you can see all of your roots as they form and keep an eye on their development. One variation of this method involves drilling a hole in your glass container, about a third of the way from the bottom, using a diamond drill bit made specifically for glass or porcelain. This hole allows you to drain out any excess moisture, protects against overwatering, and keeps oxygen supplied to your roots as they grow.
While any of these methods would be excellent choices for first-time LECA adventurers, we’re going to focus on the Inner/Outer method in this article.
Here’s What You’ll Need
All of these items should be available at your local nursery or plant store, or online. (Remember to shop local and responsibly whenever possible!)
- An inner container with drainage holes
- An outer container or deep saucer without drainage holes
- LECA
- Distilled water
- Hydroponic nutrients
- A pH testing kit
- pH UP
- pH DOWN
Preparing LECA
The first thing you need to do is estimate how much LECA you’ll need for your container size. Transfer the LECA to a large plastic bucket or container and give them a good long rinse, stirring to clean off any clay dust. Once the water runs clear, let your LECA soak fully submerged for up to 24 hours. You can use this time to rewatch Bridgerton, call your grandparents, or take a bath and think about how you are basically a plant with more complicated feelings.
Once soaked, strain out your LECA with a colander.
Transferring Your Plants
1. Remove your plant from its container. If you’re transferring your plant from the soil, it’s best to wait until the plant needs to be watered. This will keep your leaves from yellowing due to excess moisture and make it much easier to de-soil your root ball.
2. Use your fingers to carefully separate as much of the soil as possible. Cleaning the soil from your roots is incredibly important. Because LECA is a sterile environment, you don’t want to bring in any contaminants that might affect the health of your roots. So even if this feels tedious, stick with it! Your plants will thank you.
3. Run the roots under gentle water, further cleaning the soil residue.
4. Fill your Inner container about halfway with LECA, shaking or rotating to help the balls fit into place.
5. Add in your plant. While you want the roots to be well spread out, you don’t need to worry about where they’re pointed, or whether they’re covered by the LECA. They know where the good stuff is and will sort themselves out in no time.
6. Slowly add in the remaining LECA, continuing to jostle your container so that the LECA falls into place. There’s no need to pack anything down.
7. Now it’s time to add your nutrient reservoir! Your reservoir should fill about 1/3 of your container. There will be more instructions on the nutrient reservoir below.
8. Once you’ve added your nutrient reservoir, move your plant to a sunny spot in the house. Wait until the water has completely evaporated or slurped up by the plant, then add plain water up to the one-third mark again. Repeat this step for the first month, as often as the water depletes.
9. At the beginning of the second month, you can carefully remove the plant from the LECA to examine its growth. If your plant is transitioning from the soil, you may see some evidence of rot or deteriorating roots. Don’t panic! Simply trim off any rot or unhealthy roots. Healthy, fully transitioned roots should start growing in no time.
10. Repeat steps 7-9! You only need to add new nutrients about once a month.
Making Your Nutrient Reservoir
When it comes to preparing your nutrient reservoir, there are a few key ingredients.
1. Start with a large jug of distilled water and add your hydroponic nutrients according to the package instructions.
2. After a good shake, bust out your pH testing kit and pretend you’re in eighth-grade chemistry.
3. Most houseplants prefer a pH level of 5.5-6.5. If your water is a little lower, add the appropriate amount of pH UP. If it’s a little too high, add a little pH Down. PH is important because it affects your plant’s ability to absorb the nutrients available in the reservoir, which will dramatically impact your plant’s overall health.
4. Once your nutrient reservoir is pH balanced, it’s ready to use!
Tips & Tricks
If you’re transitioning your plant to LECA from water, such as with a propagate, you won’t have to worry about the de-soiling steps, but you should consider using an additive such as Superthrive to help your roots transition to a solid medium.
While it may seem backward, it’s often best to choose younger plants to transfer to LECA. More mature plants will have a harder time making the transition and may be more susceptible to shock. Additionally, the larger the root-ball, the harder it will be to de-soil, meaning that younger, more adaptable plants are usually the safer choice.
Thank you for growing with us! Please tell us about your Semi-Hydro journey @houseofplantlovers.
Jeff Miller @jeffmillr
Portland, ORJeff Miller is a writer and novelist based out of Portland, OR. When he’s not taking care of his own collection of green friends, Jeff can be found writing books, short stories, and poems and curating www.thetruthaboutgoats.com, an online community for artists and creators. You can read more of his work there, or follow him on instagram @jeffmillr.
