How to Grow Orchids In LECA

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Just a wee disclaimer before kick off – I’m mainly talking about Phalaenopsis here. There are a LOT of different types of orchids, and most of the ones we get in the houseplant hobby will do fine in leca, but Phalaenopsis tend to be the most common.

Also, this is a whistle-stop tour of keeping orchids specifically. If you want a full-on detailed guide about keeping houseplants in semi-hydroponics, read this article first.

Is leca good for orchids?

To be perfectly honest, I prefer keeping my orchids totally hydroponically.

If you’re good at remembering to water your plants pretty frequently, leca is fine. However, if you live somewhere dry, or you let the top layer of leca dry out a lot, then you may find your orchid can’t get adequate hydration.

If you have pretty high humidity, they should be totally fine.

Pros of growing orchids in leca

Less maintenance

  • you don’t have to repot as often

Orchids do NOT like being repotted, and they especially don’t like changing media/substrate. However, when you keep them in moss or bark, regular (like, annually) repotting is inevitable, because the substrate can break down and will need replacing.

Leca doesn’t break down, so we don’t need to repot. Even if we go up a pot size, the orchid will barely notice as long as you’re gentle.

That being said, the initial switch of substrate to semi-hydro can be, er, harrowing for the orchid, and it can take them MONTHS to forgive you and start to bounce back.

By the way, they do NOT like the switch to water culture, so it’s not *exactly* the easy way out, but there are benefits.

  • It’s easier to treat for pests

You can just take out the plant, rinse it/treat it like normal, and then boil the leca to be sure to get rid of any lingering bugs.

  • It can be cheaper

At least, it can be in the long run because you go through less substrate.

You can keep an eye on the roots

It’s advisable to grow orchids in clear containers because their roots can photosynthesize and help give the plant more energy. Therefore it’s a lot easier to keep an eye on the roots without having to disturb it.

This is one of the reasons I like to keep them in just water. The roots are suuuuper easy to care for.

Cons of growing orchids in leca

  • They don’t like the transition

And as I said before, they can sulk for a long time.

  • You need to keep on top of flushing

This is reason #1 leca + orchids was never really gonna work for me. I’m somewhat laissez-faire with the whole flushing thing, and my aroids don’t really care. Orchids, however, can be a little more discerning, and fertiliser buildup on the leca can lead to root burn.

  • They like their substrate to be evenly moist

Most people use the shower method for watering orchids in leca, because if you let the top layer of leca get too dry it can cause issues. Orchid roots grow in every direction, not just down, so you can end up with dry roots that are pretty ineffectual.

Sooo if you’ve gotten into semi-hydro because you’re terrible at remembering to water, then this is NOT for you.

HOWEVER, if you like to water your plants, say, every week, then keeping orchids in leca could suit you down to the ground.

  • It’s recommended that you test your pH

The issue is that orchids prefer more acidic conditions, which is why a lot of people like to keep them in moss. Leca tends lean a little more towards the alkaline end of the scale, so you need to make sure you’re testing the pH of the nutrient water.

If the pH level isn’t acidic enough, it can cause a nutrient lockout and reduce availability and therefore nutrient uptake.

This is kind of true with most plants in leca BUT if you’re growing orchids for the blooms, they’ll need proper nutrients.

How to prepare your leca for orchids

Apparently some people prepare it in a way that makes it less alkaline, but as I understand it, it’s not actually alkaline, it’s just less acidic than other substrates.

Anyway, I just rinse it outside because I don’t want to clog my pipes.

A lot of people like to boil it.

I…think just rinsing it until the water runs clear is fine. I would only boil if I’d have some sort of disease on it.

How to prepare your orchids for leca

Orchids are actually one of the easier plants to prepare for leca because their roots are pretty thick by nature. Epiphytic orchids have thick, spongy roots because they have a layer of velamen on the roots that protects them from the sun, and from drying out too quickly.

Velamen washes off pretty easily because it’s actually an aerial root (all epiphytic orchid roots are actually aerial roots by nature). Also, a lot of orchids are grown in bark, which comes away pretty easily.

If they’re in moss, it can be a bit trickier to clean them off, but the cleaner you can get the roots, the easier they’ll transition to semi-hydro.

What pot is best for orchids in leca?

It’s a matter of personal preference, so if this isn’t the pot type you like, pick one that you do. A lot of people like wicking pots, but I prefer a glass vase with holes drilled in a third of the way up.

I just find that running water into the vase and having it run out of the holes is the easiest way to flush without getting leca everywhere.

And when plants need flushing as often as orchids (every month is best, rather than, er, annually, like *some* people prefer to do) it makes sense to have a system that’s as easy as possible.

Also, glass vases/jars are pretty good at keeping the humidity in, so the leca is less likely to dry up as quickly.

(I also like the way they look! Sue me!)

How to fertilise orchids in leca

Regularly! Leca is inorganic and won’t provide the plant with any nutrients, and as previously discussed, if you want flowers, they’ll need food.

I actually don’t know if anyone makes hydroponic nutrients specifically for orchids – I couldn’t find any. You will need to use something that formulated for semi-hydroponics due to the lack of nutrients in leca.

I use General Hydroponics Flora series, and they have a little table on the bottle that tells you how much to feed. They’ve got the ratios needed for pre-flowering and flowering. I would use the pre-flowering when you have a flower spike, the flowering when it’s, er, flowering, and the rest of the time the growing ratios.

How to look after an orchid in leca

Apart from benefiting from adjusting the nutrient solution ratios depending on the flowering cycle, the same as any other plant in leca.

  • Flush it monthly
  • After you’ve flushed, fill the receptacle with nutrient solution
  • Top up the solution with plain water when required, or level it to empty out and water it weekly with plain water

That’s it.

Final thoughts

Many people SWEAR by keeping their orchids in leca, others struggle to keep them hydrated. As I said, I’m not a fan, but I think it totally depends on your approach to plant care.

If you love to nurture your orchids and really love to stick to a routine, it’s a really nice way to grow your plants. The control over nutrient levels is something that a lot of perfectionists really enjoy.

Caroline Cocker

Caroline is the founder and writer (and plant keeper) of Planet Houseplant

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