I have regularly noticed that some of my seedlings, despite growing very well, as soon as they are transferred to the main system, deteriorate and die. The stem which had started to grow well suddenly becomes very thin, dark in color and nutrient does not reach the top of the plant and it dies. I have done some research on this topic and found only one reference on a soil growing medium where there were 2 possible explanations:

  1. a fungus developing on weak plants
  2. an excess of humidity

I think the number 2 is going to be my target for testing, before attempting to kill any fungus, I will try to regulate the water a bit better.

Where could the problem be?

My CondoBox

CondoboxI have designed the following box with a level of nutrient that sits in the bottom, and a pump to move it up to the upper part, and an overflow tube where I can regulate the height to maintain a constant level in the upper part. I also have a floating device to indicate the level of nutrient left in the lower part, and a stone generating air in the liquid.

I try to regulate the level of water so that it touches the bottom of the pod with the seed in the permalite, and I come to think that this might be the problem as too much water might be sucked in the permalite. It is not really a problem if the plant is already bigger but it seems to be affecting it when it is in the very young state.

My next experiment will consist of moving the level of the nutrient a notch under the pod so that it does not touch but the plant will hopefully sense the water underneath and grow the roots into it. I will of course maintain some humidity in the top part by either regularly spraying the permalite or also by covering the plant with a translucid cover to keep the moisture trapped inside. I will report on my experiment end of november.