Emersed Vs. Submersed Aqaurium plants

[JE47]

So I know emersed plants a grown partially underwater with most of their growth i.e. leaves grown above water and submersed are plants grown completely underwater. Now for my question is it better to buy emersed grown plants or submersed or is there even a difference?

[Guppysnail]

If you intend to submerge the emergent grown plants they often take longer to transition to your tanks and have a more drastic melting before regrowing leaves adapted to survive underwater. 
 

submerged grown sometimes melt due to different parameters but their leaves are already adapted to function submerged. 
 

[Sarina]

Most plants are grown emersed at farms, so you usually don't have much choice in the matter unless you're getting them from another hobbyist or someone who farms plants submerged. Sumberged growing is much more time consuming and it complicates things by adding algae, water parameters, and light reduction into the mix. Emergent grown plants are much easier to farm on a large scale. 

In my experience, even sumberged grown plants experience some melt when transplanted. 

[Sarina]

On 9/8/2023 at 4:45 PM, Pepere said:

I sort of suspectif your water parameter, gh, kh, ph and nutrient levels macros, micros, co2 , lighting are the same or very close, melt would be far less than if there are significant differences.

Most rosette type plants will experience some type of stress symptoms when transplanted not due to different conditions, but due to having their roots disturbed. Stem and rhizome plants are much more resistant to transplant stress because they rely far less on their root structure. 

[Seattle_Aquarist]

Hi @JE47,

An excellent question and the answer is yes, there is a difference and it has to do with the leaves of the plants/stems.  Part of the leaf is called the cuticle and it allows a plant that is grown emersed (emerged) to maintain hydration by minimizing the loss of water from transpiration through the leaves while still allowing CO2 to enter for photosynthesis.  A plant/stem that is grown submerged has little to no cuticle layer since there is no need to minimize the transpiration.  If an emerged plant/stem is moved into a submerged environment the cuticle layer is actually a detriment to the plant and typically the plant will absorb the nutrients from that leaf allowing it to die and use those nutrients for new growth.  Aquatic plant nurseries (like Florida Aquatic Nursery) and plant in-vitro growing operations (like ADA and Tropica) grow most of their plants emersed however even those two methods have differences.  Plants grown in aquatic plant nurseries are grown emersed but in lower humidity environments than in-virtro grown plants and the cuticle thickness in emersed grown plants is greater than in-vitro grown plants.  That is why many in-vitro grown plants (depending on species) do not suffer the degree 'melting' that emersed grown plants/stems do.  -Roy

Growing aquatic plants emersed but with high humidity