Quote:
Originally Posted by Talila6
It would leave the old roots, unless they are really rotten. The inner threat like cores of the old roots still provide some support to the plant.
Don't be in a rush to repot, unless the mix is really old and decayed.
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Quote:
Originally Posted by derv88
Is this a fact? Why is the rule of thumb to completely cut off the rotten roots if this is the case?
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To answer derv88's question in context with Talila6's response...
Do also understand that by posting this I do not mean to make anyone feel unintelligent or offend anyone. I'm only providing evidence for what I know is based on truth. And derv88 requested the facts.
Forgive me if I'm misinterpreting what was said in the previous posts, and do feel free to correct my interpretation of the posts if it is incorrect, but here it goes...
I cannot currently find any evidence that supports the idea that a dead orchid root can still transport water to the rest of the plant. In fact, according to repeated firsthand horticultural experiences, I find the contrary to be true. From several of my observations, dead orchid roots
do not provide water to the orchid. I currently have a couple orchids that have such damaged root systems that they are practically hanging by a thread. The leaves show clear signs of dehydration and loss of turgidity due to severe root damage.
You gotta remember what constitutes a living orchid root.
1. A spongy outer layer called
velamin.
2. A thin layer of skin cells called the
epidermis.
3. A thick layer of cells called the
cortical layer (aka
ground tissue). It is also simply known as the
cortex.
4. The vascular bundle that consists of
xylem and
phloem, (basically speaking).
These tissues work in tandem to keep the plant "happy".
That stringy part of a dead root are the remnants of the plant's vascular bundle.
While xylem may not be living tissue, it may not be as simple as, "even when the roots were still alive, xylem still consisted of non-living cells, so xylem must still be able to transport water when the roots are dead, right?"
There might be a bit more to it than that, idk. And the reason I don't know is because I haven't taken high level botany courses before, so the depth of my understanding as to how xylem and phloem works is kind of limited.
I will however take this opportunity to post a video that somebody else made that will give some insight on a plant's vascular tissues.
This is a video that explains the
basics of plant nutrient and water transport via xylem and phloem:
In a dead root, I doubt the xylem and phloem are functioning as they would normally function when the root was alive.
If someone was able to cite several specific reputable sources that can provide enough evidence to support the claim that even dead roots can still transport water to the shoots of an orchid, then and only then can I truly believe that this claim is true. Until then, I'm not inclined to put much weight in the idea that dead roots can still transport water to the orchid.
As far as I know, the only thing that dead roots would provide for the orchid, is a point to anchor the orchid into the pot.
Q: Why would anyone recommend or advise someone to remove dead orchid roots then?
A: Mostly in order to prevent pathogenic fungi or bacteria from having a place to grow and proliferate, thus leading to the prevention of further root damage/death.
The second answer is aesthetics, which leads to the hobbyist having varying degrees of piece of mind, (depending on the situation).
Thirdly, it gives the hobbyist a clearer understanding of just how many roots on the plant are alive and functional in order to provide the appropriate pot size for the plant.