Question
Hello,
We live in the foothills of Northern California. We have raised plater boxes for our vegetable garden. THe box that we've used for tomatoes for three years has developed large pockets of white fungus-looking material in it. The pockets exist below the surface and can be 5"-18" in diameter. We didn't rotate our tomatoes to other boxes because I read that you shouldn't do that with tomatoes. But last year our tomatoe plants didn't produce or grow well. They didn't turn brown or die back, they just didn't thrive or produce as they normally do. A couple of plants didn't produce at all even though we use organic fertilizer. We have had some problem with our irrigation hoses dripping and keeping parts of the boxes continually wet but only the tomatoe box has this white fungus. I've tried looking up the condition in our gardening books and on the internet but can't find anything that describes this particular condition. Do you know what it is and if so, is there an organic method of eliminating it?

Thank you, Jeanette

Answer
Hi Jeanette, it is indeed a fungus.  Most people are more familiar with the reproductive part (the mushroom) and seldom see the main organism under the soli surface. Fungus needs decomposing organic matter for food which you are providing in the organic fertilizer.
I suspect most of your problem is related to your soil as it decomposes. As your particle size gets smaller and smaller, there is less space between the particles which slows root development.  If what little space you have is full of water, you get little or no root development except at the surface which dries quickly and your plants just don't perform well.  With vegetables, I'd replace the soil every other year and completely turn, loosen and add coarse organice matter (compost, fine bark, leaves etc.) the second year.  This loosening will stop your fungal problem, but the fungus is not the cause of your unhealthy plants, just a symptom of a problem which is soil compaction.  Jim