# Question on growing emerged hydroponic herb



## tiger15 (7 Aug 2021)

*I set up hydroponic herb growing bowls in my west facing window that receives afternoon sunlight.  I try both aquatic (Limophila aromatica, L. hippuridoids, and mint charlie) and terrestrial herb  (Thai and red holly basil).  They are planted in clay pellets soaked with aquarium water from my high tech tank.  

They developed good roots and were lush initially, but lately they are stunt and some develop brown tips on leaves except charlie.  Is it a sign of nutrient burnt?  Should I stop watering them with nutrient rich aquarium water but plain tap water instead.  I have no issue watering my outdoor herb with aquarium water though.*
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## tiger15 (8 Aug 2021)

So no one has the answer, so I tried to answer my question by testing the hydroponic water.  Here are the test results:

 pH 7.0, kH 5, TDS 128, PO4 0.1 ppm, and NO3 non-detectable. 

So my assumption of nutrient burnt is apparently wrong as the nutrient levels are quite low.  So can it be too much sunlight or too little humidity.  The plants receive window filtered sunlight between 300 to 600 PAR in the afternoon, and room humidity  between 40 to 60% presently. 

Are there experienced hydroponic plant growers out there?


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## PARAGUAY (9 Aug 2021)

To be fair you only posted this Saturday sure someone with the expertise will give a opinion in time. Like to know myself


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## zozo (10 Aug 2021)

How much water is in the bowls? Maybe you keep them too wet and suffocate the roots. Also after repotting and making it too wet it could be that the plant initially grows but eventually, the damaged roots that are constantly submerged will start to rot. This can cause leaf damage, viral infections in the plant etc...

Hydroponic systems are not defined by the type of substrate and amount of water you use but are defined by the watering technique and it actually should be a constant drip and drain or a flood and drain cycle with the help of a bell syphon where the substrate stays sufficiently aerated for the biggest part of the day. It should not be a puddle of water the plant constantly stands in. Or you need to go Hydroculture but then you would need larger/deeper pots where the water only is touched by some root tips. meaning the plants' main root system stays relatively dry and the water puddle is deep down in the pot.

If a plant stands constantly soaked in boggy conditions it needs a bombshell of light for the biggest part of the day to deal with that.

So in your case, i suspect and would say give less water, keep it damp and not soaking wet and stick an Osmocote fert cone at the plant base.


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## tiger15 (10 Aug 2021)

zozo said:


> How much water is in the bowls? Maybe you keep them too wet and suffocate the roots. Also after repotting and making it too wet it could be that the plant initially grows but eventually, the damaged roots that are constantly submerged will start to rot. This can cause leaf damage, viral infections in the plant etc...
> 
> Hydroponic systems are not defined by the type of substrate and amount of water you use but are defined by the watering technique and it actually should be a constant drip and drain or a flood and drain cycle with the help of a bell syphon where the substrate stays sufficiently aerated for the biggest part of the day. It should not be a puddle of water the plant constantly stands in. Or you need to go Hydroculture but then you would need larger/deeper pots where the water only is touched by some root tips. meaning the plants' main root system stays relatively dry and the water puddle is deep down in the pot.
> 
> ...


The plants stand constantly soaked as I made sure water is leveled with the top of the clay pellets,  and they get all afternoon  sunlight through my west facing window.  I pulled one  burnt basil out and found the roots rotted.  I started the basil from cutting in a pot of water, and it developed white healthy roots to begin with, but strangely, the same roots rotted in permanent soaking.  I am surprised my other wetland herbs, Limnophila aromatic and hippuridoid aka rice paddy herb, appear to dislike wet feet too even though they grow fine fully submerged in my high tech tanks.   Mint Charlie is the only one doing OK in wet feet.

So what I did was not hydroponic even though I use hydroponic clay pellets.  I will change the practice to hydroculture by letting only the bottom one third of the pellets inundated and see what happen.


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## zozo (10 Aug 2021)

tiger15 said:


> So what I did was not hydroponic



No, it actually wasn't, Hydroponic has nothing to do with what substrate is used nor type of plants or whatsoever. It's only a watering technique to make sure the plant has a constant supply of nutritious water... It's also nothing really new, it's a newly invented and popular term, but similar automated techniques are already used for many decades before anyone ever heard of the term Hydroponics, it simply means Water Works from the Greek Hydro and Ponos combined. Back in the day, it all was Hydroculture.

I know it is indeed confusing that you can keep quite a lot of plants in a vase with their roots in the water, or even propagate plant cuttings like this without any issues. What exactly happens when substrate comes into play I don't really know then I have to guess and I think the substrate causes a lack of oxygen exchange and creates a sluggish, stagnant and eventually clogged with rotting bioload and almost anaerobe environment. Once the rot kicks in it's a downhill spiral killing the plant. Oxygen or at least lose and not clogged well-aerated soils play a major role in the plant's nutrients uptake. Some plants take it better than others, but there are also bog plants that can be killed like this if the light source isn't sufficient enough. These requirements are very species depended.

Anyway depending on what watering system is used you can grow plants hydroponically without any substrate at all, growing from a Rockwool or coco fibre starter plug and their roots hanging below it in the clean but fertilized water. But as soon a substrate is used, a pot, container or a slab from whatever material, the system needs to be adjusted to have proper drainage to provide sufficient aeration in the substrate. 

Here is a nice website explaining different Hydroponics techniques.








						Hydroponic Systems: How They Work and How To Build Your Own
					

Learn the basic types of hydroponic systems and how they work. Also covered is how to build your own and the best hydroponic systems to buy.




					www.epicgardening.com
				




The only one not explained is the bell syphon flood and drain system as shown below.




As said 20 + years ago this was all under the name Hydroculture which is its synonym. Whit whom, when and how this became Hydroponics i have no idea.

This was the earliest form of hydroculture. This would be the best approach in your current setup.




I guess they needed some different names for marketing purposes.


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## tiger15 (10 Aug 2021)

Thanks for the information.  In review of the different hydroponic systems,  a common theme is to provide oxygenated nutrient water to the roots by means of circulation, wet and dry cycle, or wicking moisture to roots.

The reason aquarium plants can grow partially emerged because fish tank water is adequately oxygenated or else fish will die.  The reason cutting can develop healthy roots in  water but rotting roots in permanent wet feet is eventual oxygen depletion in stagnant inundation.  So my best option is to imitate the deep water pot culture as shown in the last picture.  But I don't need the water level indicator as the bowl is transparent and I can easily see the water level in the clay pebbles.  I don't need wicking either as the clay pebbles are porous and can draw water by capillary tension.  Let's see how the change will make it work.


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## zozo (10 Aug 2021)

tiger15 said:


> But I don't need the water level indicator as the bowl is transparent and I can easily see the water level in the clay pebbles. I don't need wicking either as the clay pebbles are porous and can draw water by capillary tension. Let's see how the change will make it work.



Yup, that will work a charm... I keep plants in glass pots like that on pumice gravel.

This is an Anthurium, but it still has its original soil clump around its roots from the pot it came in. It simply has a base layer of pumice, put the plant in and fill the edges with pumice too. I know the level and keep the water below the soil.




It also can grow on water only (The deepwater style in hydroponics)... But then for most plants that do grow this way don't overfill it the plant base should not be emersed too long. I'm not sure but might be all plants do take this. Some with fewer sturdy roots need some extra support then.





But the clay pebble is perfectly designed for hydroculture.


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## tiger15 (11 Aug 2021)

I vacuumed half of the water out of the bowls with a turkey baster, rather easy with clay pebble media, not so if I had soil.  To remove excess water from soil, you have to wait for slow evaporation or gravity drain if drain holes exist.   I had grown basil and Limnophila aromatic in unsaturated soil in the same bowls before, but they last less than a year as they are terrestrial annual.  They last even shorter if you allow them to flower.  Interestingly, submerged grown  L. aromatic is perennial.

There are many house plants such as Lucky bamboo, pathos, coleus and philodendron that can be grown permanently in a pot of water.   Additionally, their low light demand makes them specially great as house plant.   I wonder if they will do well or survive  in permanently inundated soil though as it can go anaerobic.

I have a lucky bamboo grown in my high tech tank, and an Anubia that grows out of water.  The lucky bamboo is thriving and will soon reach the ceiling, but the emerged leaves of my Anubis always developed brown edges for unknown reason.  At first I thought it was caused by low humidty, so I covered the emerged leaves up with plastic only to turn them mushy.


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## zozo (12 Aug 2021)

I also never was successful with growing Anubias emersed, same issues new leaves always dry out after a while and in all cases the plant stopped producing emerged leaves entirely. I'm still growing a bunch of Anubias very close to the surface and all rather stay submerged. It's a particularly tricky plant to get fully to transition and be happy in an emerged form in lower humidity. Failing in higher humidity might be temperature related, but that's a guess I don't actually know.



tiger15 said:


> I wonder if they will do well or survive in permanently inundated soil though as it can go anaerobic.


I'm running a project like this and tried to tackle it by not using soil but small chunks of pumice (Filter Lava) to provide sufficient cavities and some kind of circulation to prevent it from going anaerobic.








						Where The Jungle  "Destroys" Red Rock Creek..
					

What species is this lily? :)   This one...   But then a very small cutting from its rhizome... That way it stays very small for a few years depending on fertilization and light cycle... This actually goes for any lily sp. with a Marliac or Tuberosa rhizome. Cut off a small young plantlet from...



					www.ukaps.org
				



If you scroll to the start of the thread you'll see how it's build-up.

The lava chunks are covered with about an inch of lava based fine gravel and planted up. The house plants that do quite good in it is Cyprus alternifolius, Syngonium sp, Pachira aquatic, chamaedorea palm and the Mexican dwarf cyprus. The dwarf Cyprus struggled a bit for a few years but stayed alive and was finally establishing rather well. It also has a Cissus amazonica, but this plant is very light/temperature-sensitive for these conditions it always suffers in the winter and a lot dies off, but till now it always came back and grows relatively well during the summer. Fittonia even tho known to do good in tropical rainforest terrariums, is a questionable plant sp. for this setup, it's still alive but kinda suffering.

Plants that didn't like it till now are Begonia maculata unfortunately because it's a stunning plant, it's still alive actually but always suffering more dead than alive. The same goes for the Alocasia sp. zebra and several other Alocasias that didn't take it at all, tho it should be a good bog plant if enough light is provided.  Most Peperomia sp. I tried didn't take it, but i guess that's because it actually is an epiphyte most epiphytes don't like it to wet.

Trail and error stand and fall with several factors and a major one is light and then temperature... I can't say in numbers such as Watts what is enough... I guess it all comes down to PAR I can not measure and most random lights don't provide these specs. More light and stay above 15°C will increase choices and success.


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## tiger15 (18 Nov 2021)

zozo said:


> I also never was successful with growing Anubias emersed, same issues new leaves always dry out after a while and in all cases the plant stopped producing emerged leaves entirely. I'm still growing a bunch of Anubias very close to the surface and all rather stay submerged. It's a particularly tricky plant to get fully to transition and be happy in an emerged form in lower humidity. Failing in higher humidity might be temperature related, but that's a guess I don't actually know.
> 
> 
> I'm running a project like this and tried to tackle it by not using soil but small chunks of pumice (Filter Lava) to provide sufficient cavities and some kind of circulation to prevent it from going anaerobic.
> ...


I finally got the Coleus established in my hydroponic pots as I can see white roots spreading out all over in the LECA clay balls.  The trick I learned is to maintain only a small reservoir in the bottom and never allow the roots to be permanently inundated.   In my previous mistake, I pulled out dead plants with root rot from anaerobic inundation.  It’s a paradox that the same plant cuttings root out nicely by inundation in my shrimp bowls, which I attribute it to oxygenated water.  There is no water circulation in my zero tech shrimp bowls and oxygenation comes entirely from  photosynthesis of submerged plants.  

I would say pumice or crushed larva rock will do even better as they have higher water holding capacity than LECA due to greater porosity.  Nevertheless,  the clay balls are kept moist enough for root growth due to evaporation more so than by capillary tension.  I inserted a small piece of filter pad in the back as a wick to draw water from the reservoir and it helps.

I am leaving a couple coleus cuttings in my shrimp bowls as emerged growth.  Not every cutting made it though as some rooted out nicely in the beginning but stopped growing or withered away.  Coleus adds color and foliage contrast to the green submerged growth.  Interestingly, despite intense sunlight (500+ PAR) by the window, the stem plants stay green as I attribute to CO2 limitation.  

 I still have no luck getting my herbs (basil, mint and lemon balm) to establish in my shrimp bowls or hydroponic pots, but I will try another day.


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## sparkyweasel (18 Nov 2021)

I haven't tried it indoors, but Water Mint grows with its roots submerged, it might do better than ordinary mint.


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## tiger15 (23 Nov 2021)

sparkyweasel said:


> I haven't tried it indoors, but Water Mint grows with its roots submerged, it might do better than ordinary mint.


I was looking for water mint, but couldn't find any available locally.  I tried Mint Charlie, a fully aquatic stem, but it withered away in my hydroponic set up.  I guess I can get most herbs to grow if I do it the right way.  It's a learning process by trial and error.  Case in point is that my Coleus, belonging to the mint family, are finally growing well in both aquatic and hydroponic set ups.  Interestingly, the foliage color is changing.  The new leaves lose the redness of the old leaves in the cuttings, not sure if the color will deepen in summer when the sun is stronger. 

On the other hand, red stems I transplanted from my high tech to my zero tech shrimp bowls stay green, and grow at snail pace despite much higher window sunlight intensity  (300 to 600 PAR).  I guess CO2 limitation prevents stems from getting red.


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## dw1305 (23 Nov 2021)

Hi all, 


sparkyweasel said:


> I haven't tried it indoors, but Water Mint grows with its roots submerged, it might do better than ordinary mint.


I've got some that has grown for ~ two years inside. It hasn't looked great, but it hasn't died. 

cheers Darrel


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