Drying rate of Media

[Ray]

In another thread, ES stated “ Because LECA is more porous than bark, it will wick water faster from the pot, and a pot full of LECA will dry faster than a pot full of bark. That clashed with my own observations, so I thought it might make for an interesting discussion.

My thinking is that there’s “drying” and there’s “drying out”, if you get my drift.

I have had plants in S/H culture that were accidentally unwatered for as much as 6 weeks or so that were perfectly fine. The reservoir was bone dry and the LECA certainly appeared to be dry, but the condition of the plants - especially the roots - suggested that there had been some source of moisture (humidity) within the pot to keep them healthy and not desiccated. Plants in bark, when unwatered for that long, would have been far more shriveled.

Of course, a lot depends upon the specific bark or LECA used, size, porosity, packing density, etc., but I’m thinking there is surface moisture and that held internally. The former can be absorbed by the plant if it happens to come into contact with the roots, but the internal moisture can still support the plants, to a degree.

The particular LECA I had at the time apparently had internal porosity that communicated well with the surface, so it both absorbed a lot and released it well. I don’t know if the same can be said for any bark.