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A WARNING about gritty mixes

9 years ago

Over the last few months, I noticed a number of posts regarding succulents that aren't doing well in soilless media, and too often I discovered that the problem has been dehydration. I have since done several Google searches of this site, and it appears the problem is pretty widespread, and we often don't diagnose it properly.

I think we need to warn new growers, and growers new to gritty-type mixes, that under-watering gritty mixes is every bit as common and easy, if not more so, than over-watering potting soil. This happened to me when I switched a number of plants from traditional potting soil to a soilless mix, and the problem was very difficult to sort out. I also think we should keep in mind that it's nearly impossible to over-water a plant in Al's mix, or any similar media. If someone's succulent is failing in Al's mix, it is much more likely to be due to lack of water, lack of light, low temperature, or no drainage than it is to over-watering.

For example, I read a thread by grower who transfered an Echeveria to grit in a terra cotta pot, then put it in full sun and only watered it every month or so. Of course, the plant was dying. I think we put so much emphasis on over-watering succulents that new growers combine everything they've read about it - and end up dehydrating their succulents to death instead.

In my own experience, even here in cool, cloudy Oregon, my small pots of grit dry out completely in just a couple of days outside. In order for them to survive, I have to water at least 2-3 times per week. For them to thrive, I'm watering every day. I just poured off the top 2-3 inches of a small, established Crassula in a 4" pot and found no moisture despite it being thoroughly watered the day before yesterday; the temperature never rising above 65 degrees, and the sun only coming out for about 3 hours in the last few days.

From now on, the first question I ask growers who post about failing succulents in grit will be weather there is any moisture when the grower pours off the top few inches of medium.

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