I've always had struggled with mold in my cat's grass.

Now, I tried growing it in straight tab water, without nutrients. I might add some fertilizer down the road if it lives long enough.

I germinated it in a sprout glass, and when the first roots formed, I transferred it into my custom net cup and added some LECA on top.

This is another appreciation-post on how awesome semi-hydro/ LECA can be.

Today, I want to show you how my propagator dome works and how to build one for yourself very easily!

TL;DR

• It uses inorganic media like expanded clay pebbles, Seramis, pon, perlite, or whatever you choose.
• You fill small modified cups with the media and then place your seeds or cuttings in them.
• The media is completely inert and can be sterilized, so you don't have to worry about mold, fungus gnats, or whatever!
• You can't over- or underwater it, it's always moist, but very well aerated.
• This is my personal aerocloner-killer!

Why I build it (backstory)

I've always had trouble getting seeds started, especially for soil plants. They almost always got moldy and the success rate was low, especially due to waterlogging. And because I didn't want to mix soil with hydroponics, I had to search for an alternative.

Some people use rock wool for that, but I always found it too expensive and impractical.

Propagation via cuttings has also been hard for me. Like most people, I started with just a glass of water, but this very often caused rotting due to a lack of oxygen.

So, I built an aerocloner this year. This is basically an aeroponic cloning unit, where cuttings are placed in, which get sprayed with small droplets all the time. It worked really great, but my main issue with it was the noise. It needs an air pump running 24/7, which I found annoying.

I also needed a separate dome just for seeds, which feels redundant.

Many people also just place their cuttings into peat or coco, and they root very well too, as long as they get enough oxygen.

How it works

All semi-hydro substrates have some intrinsic wicking capabilities due to capillary action. This means, that if they stand in water, it gets drawn up all to the top, making the whole medium moist.

In between (and IN) the beads is a lot of empty space. Media like those can only store 30% water or so in their pores, and the rest is air. Air the roots need to breathe!

This means, that the LECA is always wet, but never water logged or compacted like coco, soil or other organic media can be!

Advantages

• Inorganic media are inert, they don't decompose or get eaten by mold or bugs
• As long as you refill the water in the tray once a week or so, you don't have to worry about too dry conditions, both the substrate and the air humidity. And even if you forget to water, it will stay moist for more than a few days after it has run dry.
• No waterlogging (anaerobic conditions due to overwatering) possible.
• Roots are already adapted for both soil AND hydro environments.
• No fungus gnats or other bugs, because they can't eat or live in the hostile substrate.
• Added stabillity for cuttings.
• No spillage, no mess.
• The LECA beads are very easy to remove without harming the roots.

How to build it yourself and use it

What you'll need

• A humidity dome/ seedling starter (available everywhere)
• A bright spot, e.g. your grow tent or windowsill
• (Optional: heating mat)
• A few small cups with lids, optimally made out of HDPE or PP
• A nail, lighter and something for holding
• Destilled water
• LECA or another medium. I like LECA with a small size (4-8 mm) the most for this use case, especially for cuttings.

Preparing the cups

• Separate the lid from the bottom
• Heat a nail and melt a few holes into the bottom. They can be very small, and 4 are sufficient. Try to make the edges as smooth as possible. Too many holes can make removing the roots harder.

• Burn a hole into the lid and but a section off. Otherwise, it will be hard to remove.

• Fill it up with your medium
• Turn it around, take your cutting and push it into the hole while shaking lightly. That way, the stem will just slide into it without effort. Turn it again and give it another small shake. The medium is now locked up and the cutting can't move.

How to use

• Moisten the LECA with a spray bottle. If they are dry, the wicking won't work as great or will take longer.
• Try to water the tray, not the top of the substrate at first. Fine seeds might get washed out otherwise.
• You can just sow the seeds directly onto the substrate and put the lid on it. As soon as they germinate, the roots will "burrow" themselves very lightly into the pores of the hydroton and be fixed there.
• Some heating from below with a heating mat is beneficial

Here are some pictures of a cactus (right after germination) and some cuttings (Tradescantia, hops, Ctenanthe) I made just a few days before:

One thing that always gets told is "Hydroponics is very clean and doesn't need microbes".

Sure, mycorrhiza shouldn't play as much of a role in hydro as it does for soil. The plants get all their nutrients directly from the fertilizer, and waste products should get flushed out regularly.

But, especially in the beginning, I always had trouble with root rot. Besides leftover organic matter and insufficient aeration as possible culprits, I think not having well established beneficial bacteria/ fungi was one reason the pathogenic microbes took over and killed almost everything in the container.

To counteract this, I recently bought water soluble microbes (a mix of dozens different fungi and bacteria) and tested them, especially in semi-hydro.

I'm not sure if it had any effects. For the already established plants, the effects were way less significant than for new ones.

One thing I definitely noticed is the very pleasant "earthy" smell, similar to a rainfall in the summer, when I stick my nose into the substrate.

And, those plants, where the roots got damaged (e.g. my ginger where I continually harvest, or recently transitioned plants with leftover soil) got some fungus gnats. Really not a lot, just here and there one or two, but there are some! They also disappeared a few days later and didn't multiply.

The thing is, many hydro growers put A LOT of effort into keeping everything very clean. Some even proposed to include the ORP value (oxygen reduction potential) just as much as pH and EC, because it tells you how hostile the environment is to microbes and/ or how well stuff can decompose.

I just don't know how I should keep my setup THAT clean outside. It's just normal for me that small insects, leafes and other stuff fall into my reservoir.

And this litter needs to decompose somehow. And I'd rather have it decomposed by a well established microbial culture than some pathogenic stuff that lands on there.

Am I just messy, and I should take hygiene more seriously, or is this totally fine? What's your point of view on this topic?

I've become a huge fan of semi-hydro over the past year.

I've planted all of my 50 house plants into LECA (expanded clay pellets) or pon (special gravel mix consisting of lava rock, pumice, and zeolithe), and they're doing absolutely great. (Too great if you ask me. They've become a weed in my apartment 😁)

Recently, I got into carnivorous plants.

Literally everyone is growing them in turf/peat or moss based substrates, and nothing else. As we all might know, those substrates not only attract pests (fungus gnats, etc.), but are not that great for the environment.

This is why I came up with the idea of using hydroponics.

As soon as I began researching, I've come to the conclusion, that there's sadly pretty much no overlap between the hydroponics community and carnivorous plants community.

So, I started an experiment.

I've put my just-bought Sarracenia, previous in soil, into pon with a very small grain diameter. This keeps the plants very moist, way moister than LECA would, at least the big marbles.

I soaked the granules with distilled water a few times, and then added a drop of diluted phosphoric acid to a pH of 4,5 and EC of 0,1 mS.

This is how the roots look after not only one week:

And the plant itself:

Pretty good if you ask me!

Sadly, Sarracenias need to hibernate, and this one started going crispy even in the store, which is apparently normal, so I've put it into my cold garage for a month or two.

I also started growing Drosera and Sarracenia from seed, but they didn't germinate yet. I got a lot of different seeds from a hobbyist, but growing CPs from seeds is a huge pain from what I've read.

Here's a picture of my seedling/ cutting station: I will make a post about the station soon!

I also sew a few of them directly into the pot and covered it with foil.

In theory, the combination of fine substrate with high water level should provide the plants with enough moisture, while also letting the roots get exposed to a lot of oxygen, which keeps them very healthy.

But swamp plants are just different maybe, I don't know. Let's see...

And, last but not least, I bought two Nepenthes a few days ago. I already placed one of them into LECA (8-16 mm).

They apparently grow similar to orchids, and not like swamp growing plants like venus fly traps or Drosera. So, they rather need a airy substrate, normal pH (about 6) and even tolerate fertilizer.

They looked like this when I bought them:

I will keep you all updated!

Tags for search engines: LECA, hydroponics, hydro, semi hydro, carnivorous plants, VFT, Sarracenia, Drosera, Dionaea, Nepenthes, fertilizer, experiment, inorganic media, peat alternative, pumice, Seramis, pon

I have been contemplating to set up a small vertical hydroponic system, but I am struggling a bit to come up with plants I would actually like to eat that would fit well.

Stuff like tomatoes or pepper just seems to grow way too big to function well in a typical vertical setup, and I am not a big fan of leafy salads to eat.

I found a nice small cabbage (Japanese Tatsoi), which is quite ok, but other suggestions would be welcome.

I bought a few bulbs two weeks ago and planted most of them into LECA (indoors) or soil (on my balcony), but also one into a Kratky pot.

I don't think I can harvest this year yet, but we'll see.

In this one also grows garlic and strawberries. It's meant to hibernate this winter, and then in the early spring, I'll place it outside.

"Indoor plants not only add a touch of greenery to your living space but also purify the air and boost your mood. While traditional soil-based planting is popular, growing plants in water, known as hydroponics, is gaining traction due to its simplicity and aesthetic appeal. In this guide, we’ll explore which indoor plants can be grown in water, how to care for them, and other useful tips for successful hydroponic gardening."

cross-posted from: https://slrpnk.net/post/12178994

For those of you who are doing hydroponics, what do you think of this system? Is it a good system for a beginner on a budget? Or is there a better system?

I have recently started playing with hydroponics in my balcony. I had success with jalapeños in a simple bubbler setup. Also tomatoes worked great in an ebb and flow system. Basil works, coriander is a bit iffy, dill does not grow. How do you know what will work and which plants need what kind of nutrients?