How can I kill a plant by overwatering it, yet propagations of the same plant will grow in water?
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Humans need water to live. But if we have too much water or the water is distributed poorly (down our lungs), we die.
If a seed chooses to sprout, it liked that’s spots moisture, temperature, and nutrient density. Changing a plants environment too quickly puts them into shock, just like a fish moved from one tank to another if the water is 5° different.
You suffocate it.
Growing in water is called Deep Water Culture. You need an airline for it to work properly. If you overwater a plant, you suffocate it because the water displaces air around the roots.
Off topic a bit but I grow aquatic plants and when I give clipping to friends I’ve seen the plant melt and grow with different shape leaves and colours too because their water chemistry is different.
Lots of answers on here but I haven’t seen anything that touches on the actual issue. As long as the roots have oxygen, they will survive. This is how roots can grow in water, because the water is in contact with the air to exchange oxygen. The issue is when the soil is made of of things that can rot. Most “potting soil” that is sold at the store is ground up trees, which will rot when continuously wet. When the wood chips in the “potting soil” rot, they use all the oxygen, and the roots around it die. If there is nothing in the soil that can rot, then there is no such thing as overwatering. If your plants live in a well drained sand/silt/clay mixture, you can water as much as you want and the plant will never ever rot. Water has oxygen in it when it rains or we water, so there has to be something in the soil to use up that oxygen to kill the roots. Growing a plant hydroponically (roots in pure water) is the fastest way to grow a plant because the roots have unlimited water and oxygen. The most lush place on Earth is the rainforest, where it rains everyday, and the soil never dries out, yet the plants seem to do OK there (because the roots are in soil made of minerals that don’t rot, and the leaf litter, mulch, compost etc is all sitting on top of the soil where it can rot into compost with access to oxygen). This whole “wait until your plant is dry before you water it or you’ll kill” thing is only because they sell potting soil that is full of things ready to rot if they stay wet too long. If your soil is made of minerals and therefore can’t rot, there is no such thing as overwatering.
Here are a couple videos that explain this:
[https://www.youtube.com/watch?v=KHZHy3_7PPE&t=2s](https://www.youtube.com/watch?v=KHZHy3_7PPE&t=2s)
[https://www.youtube.com/watch?v=MuFehTDAIAE](https://www.youtube.com/watch?v=MuFehTDAIAE)
Roots, like all plant tissues need oxygen and wet soil does not have enough oxygen in it for plant roots to survive. When some root tissue dies from lack of oxygen, microbes can infect the root system and cause additional rot.
So why is there enough oxygen in a glass of water, but not in wet soil? Well, oxygen can dissolve in water, but it does so pretty slowly. If the oxygen is used up slowly, the water will absorb enough new oxygen from the air above to keep the roots of the cutting alive. In soil the roots have to compete with microbes for that oxygen. The microbes in the soil have plenty of food (soil organic matter). Because the microbes food, they can use up more oxygen. This meas that roots in the soil get outcompeted and die due to lack of oxygen.
Plant cuttings will be happiest if you give them fresh water regularly. In hydroponics, air bubblers are used to make sure there is plenty of oxygen for the roots.
Plants that grow in wetlands have special adaptations that help the roots get enough oxygen. Rice for example has air passages in the roots called aerenchyma that act as snorkels and bring oxygen down to the roots.
It’s similar to, if you took a shower versus sitting in a bathtub for four days. You would also rot. Your environment has changed and now bacteria are top dog.
When roots are next to dirt and soaked, the roots will rot because of all the organic material and organisms in soil. “Root rot”.
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