Growing Orchids in Leca

If you’re unfamiliar with Leca, the term is short for Lightweight Expanded Clay Aggregate.

In easier terms, they are pebble-like clay balls that have been baked at a high temperature till they crack and pop like popcorn.

The high temperature helps harden the outside while simultaneously creating thousands of microscopic pores and a semi-hollow core within the leca balls.

When sitting near each other, leca can share the moisture they have absorbed from their surroundings.

This unique structure of leca allows them to attract and soak up water effectively, thus keeping the media constantly moist without causing any root rot.

And because the leca system is completely soil-free, it also reduces the chance of contamination with unwanted soil-borne bacteria and pests.

The best thing about these clay pebbles is that they are reusable!

Simply give them a thorough cleaning, followed by a treatment of hydrogen peroxide or alcohol to remove any bacteria or plant residue, and let them dry before the next use!

No longer will you have to stress over under or overwatering your orchids.

Leca’s structure, however, also has several flaws. The porous nature of the leca makes them exceedingly light in weight. For this reason, if your plant is larger than usual, leca balls might not be the ideal option for stabilizing it.

Can leca be used with orchids?

Of course! Leca systems are real game changers for new orchid parents.

Because leca balls don’t degrade over time like other media, there’s no need to replace potting mix once in a while. And since watering is a well-known painful task when caring for orchids, leca can make it much easier!

But there are also certain drawbacks when using leca system for orchids, such as the possibility of salt buildup, the pH level of water must be maintained, and greater care must be taken when it comes to nutrient requirements to avoid deficiencies.

Most tropical orchids can easily adjust to leca, especially those epiphytic, lithophytic, and semi-terrestrial varieties. Many species fit right under this category, such as Dendrobiums, Cattleya alliance, Oncidium alliance, Paphiopedilums, and Phalaenopsis.

Aesthetics aside, growing orchids in a glass container with leca pebbles also allows us to examine their roots up close.

Be very careful when moving orchids to their new house!

It takes some planning and preparation to successfully move an orchid from an organic potting media to leca.

Be very careful not to damage the roots as you remove the potting medium. Any organic material left on a root, such as soil, sphagnum moss, bark, etc., will eventually decompose and encourage fungal development within the leca beads, so be sure to remove it all.
Cut off any rotted roots and keep the healthy green ones.
Give your roots a nice hydrogen peroxide bath to disinfect the root system and treat rotting areas.
If your orchid shows signs of severe leaf rot or stem rot, you should not transfer it to semi-hydroponics. In that situation, you should probably just let the plants dry out in their current potting mix and cure the rot first. Then consider transferring them later when the plants have recovered.
Give your clay pebbles the same thorough washing with water to remove extra clay dust and then a final soak in hydrogen peroxide to kill any bacteria that may have settled on them.
Carefully place the orchid in a glass container without drainage holes. The container’s bottom should be lined with a thin layer of leca pebbles. You’ll be adding a small amount of water and draining it daily throughout the initial transferring phase.
Only when the plant has gradually acclimated to its new home will you be adding more leca beads.
Fill the glass container with leca balls, just enough to cover the orchid’s roots.
Use purified water to water the plant, and then drain it after letting it sit for two hours. Repeat this process for about two weeks.
Because the roots were disturbed during the relocation process, root loss can happen. To speed up the new roots’ establishment, you can apply a root promoter designed for hydroponics.
When your orchid begins to send out new roots, you can then switch to a semi-hydroponic setup by filling the pot with leca beads and maintaining a steady supply of water at the base of the container.
It will take about 2–3 weeks of consistent watering to fill the bottom layer to just below the root tips.
Invest in pH meters, pH regulators, and orchid-friendly hydroponics fertilizers for the best results for your semi-hydroponic orchid.
Give your orchid at least six months to a year to fully adjust and learn to love its new home!