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Asked by Community Member ·May 22, 2018 ·18.1k readers

root-drowned fruit tree

I have several sick and dying avocado trees that I believe are drowning underground.  I would love to save them. I've know there is a KNF recipe for this situation, using IMO4 and biochar.  I remember the procedure--to dig four holes at the drip line and fill with a mixture--but what are the measurements/ratio? should the two be pre-fermented together and for how long?  do I add anything else to the mix? Thanks for your help

fruit-trees biochar root-drowned avocados imo4-applications

The answer

Drake Weinert Foundation · May 31, 2018 ✓ Marked as the answer
A lot of good questions here! As far as I know, Master Cho has given a prescription to solve the issue of drowning roots by spreading IMO4 and watering with the appropriate soil treatment solution around the drip line extending out 2-4 feet in a donut shape. This area should also be treated with an appropriate mulch to help the microbes dwell here and subsequently improve the air and water flow of the soil. As I recall, Elaine Ingham was the one recommending to drill holes on the cardinal points and to fill them with cinder and 'good' compost. To answer your questions specifically
what are the measurements/ratio?
I'd follow Master Cho's potting soil mix
  • 30% cinder
  • 30% imo4
  • 30% leaf mold soil
  • 10% biochar
should the two be pre-fermented together and for how long?
"Charging" BioChar before agricultural use is recommended by top experts in the field. I have heard one recommend composting it with at least 2% fish meal or comparable nitrogen source and letting it heat up and naturally cool down. This functionalizes the charcoal and that has many benefits. see Josiah Hunt on Local Natural Farming Inputs
do I add anything else to the mix?
Love. Love must always be added to the mix!

From the KNF library

From the KNF library Drafted by Claude from Office Hours and the books · Sep 2026 · 4 sources

The library does not describe the four-hole method. It gives a drip-line ring for orchard trees, and it says not to bury IMO. (Cho's Solutions, p. 14)

  • Make a 2 ft wide ring around the drip line. (Cho's Solutions, p. 14)
  • Per 100 sq ft, spread 5 lb IMO4 and 3 lb biochar in week 1, with 5 gallons of water. Water 5 gallons again each week through week 4. (Cho's Solutions, p. 14)
  • Use functionalized biochar. Lightly cover with mulch once spread. (Cho's Solutions, p. 14)

The biochar goes in when IMO4 is made. Break up the IMO3, mix in 10 L of biochar, then mix that 1:1 with soil. (Unravelling the Mysteries of KNF, p. 59) The pile sits another 5 days. (Unravelling the Mysteries of KNF, p. 59) Pre-inoculate any mulch with IMO4. (KNF Demystified, p. 16)

For a drowning tree, Drake says to dig out the amendments packed into the planting hole and open airspace so roots get oxygen. (Office Hours Ep. 131, 17:41)

The library gives no hole-fill ratio and no fermenting time for a biochar and IMO4 mix. It does not say how much IMO3 goes with the 10 L of biochar. This chart is a soil-foundation recipe and does not name drowned roots.

Sources

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