You Don’t Need Soil to Grow Houseplants (Especially Orchids)

Yes! In fact, for some plants, I actually find it easier to grow them without soil. Or any substrate at all. Just in a jar, roots out.

It’s *technically* possible to grow any plant without soil, but it’s not really practical for most of us.

However, some plants (one in particular, which I’ll cover later) thrive being kept bare root, and it might be easier for you to do so.

orchids grown without soil

Why do we grow plants in soil?

  • It replicates how they grow in the wild

Ok, it’s a bit of a stretch to say that growing a plant in a pot of soil is replicating it growing in the wild, but it’s…similar.

As far as is practicable.

Plants are, by their nature pretty adaptive.

Even if the soil we use isn't exactly the same as what they'd grow in in the wild, we can replicate its properties. 

Things like the texture, pH, and nutrient levels can easily be replicated. 

We can adjust the water retentiveness (?) so the plant can get as much water as it needs depending on things like the season and how often we water.

It doesn’t really matter that what the plant is growing in isn’t exactly the same. It’s providing the same things:

  • nutrients
  • stability
  • water to the roots
  • Convenience

Growing plants bare root can be a pain.

On a practical level, stability in a plant is really, really helpful.

The fact one isn’t constantly wondering if one’s plants are going to fall over in the middle of the night is something I used to take for granted.

It’s also easier to keep plants as they are. Sure, they’re adaptable, but whilst they’re adapting, they’re vulnerable, and a hissy fit is always just a missed watering away.

Anyone that’s ever changed anything to hoya can attest to that (have you noticed how the first couple transfer like a dream to lull you into a false sense of security?? Tis a scam).

  • Roots prefer to grow in the dark

Roots can grow in the light with no problem, but they grow faster and stronger when they’re kept in the dark.

Personally, I like a clear pot.

I like seeing what my roots are up to, especially in a plant that has untrustworthy roots (looking at you, Thai Constellation).

You might be thinking that if roots like the dark, surely a clear pot is a bad idea??

I think it’s fine, especially in a plant that’s prone to root rot. Plus, there’s soil in there that keeps the centre of the pot dark (or darker than say, water would).

Basically, roots prefer the dark, but if growing them in the dark isn't working for you and you're getting root rot, or dried-up bits, you're better off growing them in something transparent.

What are some alternatives to growing plants in soil?

Leca

I have an article here on the benefits of leca over soil, and it’s definitely a preference thing.

If you like organisation and order then leca will be right up your street, but it’s not easier than soil…just different.

Perlite

I don’t recommend plants in perlite because it gets grim and algae-fied super quickly.

It’s a great medium and good for propagating plants (or using as a medium in a propagation box) but not, in my opinion, particularly good as a substrate for large plants.

Moss

Similar to perlite. Also, moss tends to run on the acidic side, so you could have issues with nutrient lockout if you’re growing in moss long-term.

Water

Love growing plants in just water. Growing plants in aquariums is also a great option.

As a lazy person that doesn’t remember to change the water often enough, I add java moss to my plants in water to oxygen the water. I also have some little aquatic snails that work as a cleanup crew. I have no idea where they came from – probs eggs stowed in on the moss.

monstera roots in water

These are the roots of my Thai Constellation. Growing in water really seems to suit her.

Nothing

Ok, I only have one plant that I keep totally bare root, and that’s my Phalaenopsis orchid.

I can keep Phalaenopsis alive perfectly fine, but I can’t get them to thrive and therefore rebloom. Keeping them barefoot seems to be suiting us both fine – it’s actually just started to grow a third flower spike

Why can you keep orchids bareroot?

There’s a couple of things that make keeping Phalaenopsis orchids bare root pretty easy.

The first is the nature of the plant. Phalaenopsis are epiphytes. They don’t have any subterranean roots, i.e. ‘normal’ roots that grow underground. All of their roots are aerial roots. They naturally grow on trees, using their roots to both cling onto their host and absorb water and nutrients.

Whilst Phalaenopsis can thrive being kept bare root because that’s how they naturally grow, it can be a bit of a pain taking the time to soak them – I can totally see why people prefer to keep them in potting mix or orchid bark.

However, the second reason I like to keep them bare root is that the roots turn green when they’re hydrated and photosynthesising. When I notice that the majority of the roots are silver again, I give the orchid a soak. I usually soak it in nutrient water.

I wouldn’t say it’s an easy plant to keep bare root (it can be a pain to keep the flower spikes upright when there’s nothing to anchor the stake), I just find it easier to care for when kept this way.

I don’t really have any desire to keep other plants this way, but you can try it if you fancy.

Benefits of growing plants without soil

  • It’s less messy
  • You can control all the nutrients to give them
  • Great for plants that perpetually have root rot.
  • Great for epiphytes. I’d love to try growing hoya this way – I just need to work out how to keep them upright – they have tiny roots and heavy leaves. Perhaps I need to grow them on a piece of wood or something??

How to care for a plant that isn’t in soil

The principle is the same here – you need to add water and nutrients, the difference is that you don’t know when to water.

Phalaenopsis are super handy because they turn green when they’re hydrated. Other plants aren’t so helpful.

Over time you’ll learn the difference between dry and hydrated roots, but because you soak the roots for an hour or so, root rot shouldn’t be an issue – most of the time they’re exposed to plenty of oxygen.

Therefore, you can pretty much decide on a schedule and adhere to that.

I would say a twice-a-week soaking is fine for most plants. I use nutrient water on my orchid about every two weeks.

It will depend on humidity levels, but the great thing about keeping the roots in glass jars is that the humidity in the jar stays quite high.

You could even try an aeroponic setup, where just the very ends of the roots sit in water, but most of them are exposed to the air.

If you’re one of those people that likes to spend a lot of time around their plants and caring for them, and you love more unusual plants, keeping bare root plants is a great alternative to dropping hundreds on rare plants.

Final thoughts

Do any of you keep any terrestrial plants bare root? I’d love to hear about your care routine. Also, apologies for any barefoot instead of bare root typos. My spell check and I are battling against each other and I think it’s winning.

Caroline Cocker

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

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