# Reasons for aerial roots forming above substrate



## Hoppy (Dec 24, 2005)

Stem plants all, as far as I know, send out aerial roots. It is just part of how they grow and reproduce. For example, if times get rough for the plants in nature, they break apart and float to new locations, staying alive as floaters, but hopefully becoming "grounded" where more nutrients and light exist. Then they re-root there.

Some stem plants, like Lobelia cardinalis,small form, hide the aerial roots inside a covering of leaves, so you don't even see them. Most will eventually become a mass of those roots near the bottom of the stem. Then you need to prune off the top, replant the top only and discard the bottoms. And, some people just try to keep lower growing plants in front of the aerial rooted ones to hide them.


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## mcd19 (Apr 30, 2007)

Thats normal for stem plants. It does not necessarily mean that they are nutrient deprived. I just remove the roots every time I do a water change. It takes just a couple of minutes and does not hurt the plant or its growth. If you have a lot of stem plants and don't stay on top of removing the aerial roots, it can become an over whelming task and in my opinion an eye sore. There are some that don't mind the aerial roots and let them grow out. I guess its a matter of taste.


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## talontsiawd (Oct 19, 2008)

All my stem plants grow aerial roots, my non stemmed don't. I assumed it was normal, which sounds like it is, don't worry about it. I tend to trim them every water change until i get bored of it. The grow back like crazy at first but slow down, i assume this is because they are rooting under the substrate. I'm not sure that you should trim them, i just do personally.


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## Bugman (Jan 7, 2008)

Interesting discussion. Sounds like a consensus so far. Hoppy's statement about plant reproduction and survival certainly make sense and sounds just like Mother Nature at work. 

I have gotten into the habit with a lot of my stems of pulling the stem up, cutting off the bottom and replanting. A lot of them grow so fast that I do this with the weekly water change. This way the areial roots (I learned a new term, thanks) don't form, at least not to any significant degree. Doing this means that I don't get the benefit of multipling my plants though unless I were to also replant the base somewhere else to get new shoots off of it.


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## Left C (Nov 15, 2003)

Last year I found a group of stem plants growing horizontally near the water at a local creek. Roots were coming out at the nodes to anchor itself in the mud/soil. This helped me to understand a little bit more about aerial roots.

Normally those plants would be submerged, but we were having drought like conditions in NC.

I grabbed up a handful and put them in a 15g tall with a 55w GE 9325K bulb and pressurized CO2. The plant started growing upright very quickly. Now, it is very pretty. It looks like an orange version of _Rotala macrandra_.


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## ikuzo (Jul 11, 2006)

most of my crypts do that i think it's normal


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## Hoppy (Dec 24, 2005)

Left C said:


> Last year I found a group of stem plants growing horizontally near the water at a local creek. Roots were coming out at the nodes to anchor itself in the mud/soil. This helped me to understand a little bit more about aerial roots.
> 
> Normally those plants would be submerged, but we were having drought like conditions in NC.
> 
> I grabbed up a handful and put them in a 15g tall with a 55w GE 9325K bulb and pressurized CO2. The plant started growing upright very quickly. Now, it is very pretty. It looks like an orange version of _Rotala macrandra_.


If you grow H. porto velho for awhile you get a new perspective about aerial roots too. That plant grows along the substrate and each node sends out the typical hygro aerial roots, but this variety has those roots head straight into the substrate to anchor the plant. 

Everything that grows evolved eons before we ever set up a planted tank, so all of the features of our plants must have developed for a purpose other than what we see in an aquarium. I can't believe aerial roots' purpose was to peeve us so much we take the plants and toss them in the nearest stream. (We already know how effective that is at spreading the area those plants can grow in.) I'll bet they are there for natural contingencies.


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## Avalon (Aug 14, 2004)

I've been studying this as of late, and here's what I've come up with:

Most stem plants will produce a certain amount of aerial roots. Usually, roots serve as roots, not as random off-shoots for sh*ts and giggles. As a plant matures, the lower part of the stem will create more and more roots at the internodes. If you were to prune your plants regularly, including uprooting the stems and replanting the tops, you can eliminate a large part of the lower roots. But what about those that appear half-way up the stem?

I tend to find this to be a growth issue. I've successfully been able to replicate the growth of these annoying aerial roots. For me, it's usually when nitrates dip a bit since I run my tanks on very tight nutrient tolerances. If I skip a dose, out the roots come. However, this is not the only reason. If any parameter, usually from CO2 or nutrients, causes the plants growth rate to stall or slow, the roots will show up.

This observation has taken me a lot of time to finally come to a conclusion with (years). It appears that plants are more sensitive in their needs and can react much more quickly to their environment than previously thought. I suspect that the roots show up because they are searching for more nutrients in the substrate if they aren't getting exactly what they need in the water column. However, I think that when you acclimate a plants to a certain growth rate, any deviation from positive will cause the plant to do what it can to sustain itself before it sheds excess biomass. Without going into a large amount of detail, this serves to reinforce the idea that tanks are continuously variable, and if conditions aren't adjusted to on a daily basis, you see stuff like aerial roots and minor algae issues.


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## Characins (Feb 4, 2008)

Interesting point Avalon.....

All I have noticed, is that my hygros send out roots like crazy, all the time, and its a pain to keep getting rid of them....I assumed it was normal but what do I know?


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## @[email protected] (Oct 24, 2007)

midway roots occur for me only for 2 reasons:
1. the plants was unhealthy, had stalled growth, or lost its growth tip, and is making side-shoots. at the base of those sideshoots are roots, because the stem serves only to bring nutrients from the roots to the leaves, and hold the leaves up. i think the plant is trying to cut out the middle man which it must still feed. when this happens i cut off the crown of growing tips when the reach an adequet size (this usually causes a crown of multiple sideshoots, not just 1 or 2), and replant them instead of the old stem.

2. the plant goes horizontal. whenever a plant starts to grow horizontal (usually at the surface, but not always), it grows roots down from the horizontal part. but if the plant is a carpet or midground bush, then we want it to do so (like HM or glosso), if its background, you should keep it trimmed shorter then the surface anyway.


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