WHOA WHOA FOLKS!!! RE-CHARGING SOIL IS DETRIMENTAL TO ITS ABILITY TO DRAIN PROPERLY. This is news to me but it comes from FoxFarm’s own soil scientists as well as a confirmation from a friend who is also a soil scientist. (Professor of Soil Sciences) I am spreading the news around the site as it is SO important to get out. I lost 56 successfully germinated seeds this year due to a hydrophilic soil condition brought on thru re-charging and sanitizing efforts that slowly drowned all my plants this season. Here’s the stuff from THEM; THEY CONFIRM MY SUSPICION THAT THE SOIL WAS TOO DENSE AND HYDROPHILIC. The raking I had done to “sanitize” the soil after the 1st round of failures exacerbated the problem, breaking soil and all the leftover hyphae into dust. The mycorrhizal supplementation leaves quite a bit of hyphae, when broken up form blockages in the soil.
Periodically fresh potting soil is really the best choice
From FoxFarm; “We do not recommend reusing FoxFarm soil, and we agree that the recharged soil should be disposed of…” !! MUST DISPOSE OF ALL SOIL ANNUALLY!!! SAY WHAT!!
I also have the advantage of a friend who is a Professor of Soil Sciences. His response:" THE ANSWER; your ‘potting mix’, ‘potting soil’, ‘rootzone media’ etc. is likely dominated with an organic fraction such as sphagnum peat moss (my preferred choice), or some kind of composted forested waste which I avoid as much as possible. With time the organic material in pots decomposes slowly leaving behind finer organic particles which are capable of greater water adsorption due to greater surface area. We use the term hydrophilic primarily to describe compounds that are attracted to water and do not repel it as hydrophobic compounds do. Hydrophobic compounds such as waxes, silicones, and such do not dissolve in water but actually repel it. Solarization can be used to sanitize but not completely sterilize soil, but it takes prescribed lengths of time and temperatures to be successful. Growing successive crops of the same species can, of course, result in a buildup of rhizoctonia, phytophora etc. root or seedling diseases, and along with poorer drainage, you are fighting a losing battle. Also, air/sun drying of organic potting soil is notorious for becoming hydrophobic and actually will repel water for a while until it reverts back to being able to adsorb (surface phenomena not absorption). Fungal hyphae are also hydrophobic resulting in water-repelling and thus the floating of the hyphae as you described. The clogging of pores is very real and most likely just the finely divided organic and inorganic particles filling the aeration/drainage pores which are critical for aeration of a soil. Bottom line as my wife started expressing to me many years ago that her houseplants ‘needed a soil change’. This is a typical progression of using potting media. natural soil has much less organic matter and through time develops a structure that balances macropore (aeration) to micropore (water adsorption) spaces. Although removing the potting soil and mixing and aerating and making an effort to enhance drainage and aeration characteristics by adding more sand, perlite, or vermiculite is seems like a noble cause the fact of the matter is you are working with a ‘muckier’ organic fraction. Organic materials as they decompose progress from a lighter fluffier material and browner in color to a blacker more finely divided material which is denser with greater water holding capacity but yet it is muckier. You can look up naturally occurring histosols being from fibric, to hemic to sapric and for example, in Florida, they are referred to as ‘Muck’ soils."
THANK YOU PROFESSOR AND FOXFARM FOR YOUR TIME, STUDY AND RESPONSE. IT WILL COME AS A SHOCK TO MANY GROWERS TO HEAR THAT SOIL RE-CHARGING IS LESS EFFECTIVE THAN RE=TREADING RACE CAR TIRES!! THAT WE MUST BUY NEW SOIL EACH SEASON!!! WOW!! I GROW IN BIG BUCKETS, THAT WILL BE A LOT OF SOIL!!$$$
Sorry for the bad news, but I HAD to share it with you. I’m thinking of changing to a substrate without lots of organic material, just coco coir and perlite, then add what I want according to the plants needs and time of seasonl. Surely this mix could be washed and recycled!? GDub