Amended Planting Hole Risk Mitigation

Hi folks. I understand why many experienced growers recommend against putting amendments in the back fill soil or planting hole but I have a couple more pointed questions I can not find answers for. The questions are around transplanting, currently containerized, Fruit Trees and Blueberry bushes. If you could provide some guidance or education I would be grateful.

A bit of information about the planned pruning and canopy size up front since that may impact the amount or size of the amended area recommended, I have 10 trees…

  • 1-Peach - Open Center
  • 2-Apples - Espaliered
  • 2-Pears - Espaliered
  • 5-Cherry - Open Center (3) \ SSA (2)
  1. Assuming my grass is meh and I don’t mind tilling it up, Is there a circumference or area and depth that we could modify to Kick start the fruit trees and proactively improve drainage that would reduce the risk of the tree roots circling?
  • I was planning to do a simplistic version of a Hügel bed but with mostly sifted soil (I have some massive rocks) and amended soil mostly to fluff up the compacted soil.
  • I have to bring in some soil to build the soil level up for the 6-8” raised boxes anyway so I was afraid that alone could cause issues and would like to mitigate the risk.
  • I am mostly concerned about my 5 Cherries (Z-dwarf, Mazzard, Malheb-sp?) as I know they really dislike standing water.
  • I’m an over-thinker so please bear with the stupid questions.

  1. Are there amendments that can be added such as Rock Phosphate, Peat Moss or Worm Castings that are less likely to cause issues?

  2. Regarding new Blueberry transplants from a Container, I spent the last few months prepping a Dug Down style Hügel bed and letting it become properly acidic; based on my reading of how nutrients become more or less available based on the Ph, do you see any reason not to put an 8th or Quarter cup of Rock Phosphate and the same with Worm Castings into.the planting hole? I have attached my initial soil test report for more reference as that may provide details for other needs I am not familiar with. Please note, my Ph is roughly 5.3-5.5 at this time for the Blueberry bed, not 6.0. Also, it states the crop is Blueberries, but that was only to separate their recommendations for the various crops I listed as growing. My apologies if you already knew that, I am new to soil test reports.

Again, thank you all for your time and consideration.

-JimmyG

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AngelOreo - I have not found one major East Coast Nursery that is against amending the soil and many recommend amending soil. Nurseries that come to mind include Cummins and Holly Brook Orchards that recommend amending soil. The rule should be this simple - if you have poor soil amend. Pick your number but generally 30 % to 40% is the max percent you want to amend because potentially you risk the roots not growing outside of the amended soil area or possibly water logging problems. The reason why I am somewhat vocal about this is that I wasted years trying to grow fruit trees in hard clay based soil and ended up with runted trees. Amended soil and in some cases using 4ft x 4ft x 1ft raised containers and most of my runted tree problem is gone. I am outspoken on this in the forums, but if you have poor soil amend. Edit - most of what I amend with is processed or aged manure. Supposedly manure will rot the roots but this does not seem to be the case with processed/aged manure. Do not use “hot” manure.

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Thank you for the input. I was “thinking”, always dangerous, of amending the soil to be 50% native, 25% locally sourced topsoil, 10-15% leaf mold\mulch and the remaining 10-15% Peat. My goal, dig about 18" down in a 39x39 square and then sift and amend the soil as noted above in hopes of having the bed settle in at about 8" about the native soil level.

I was originally going to make it 24-36" deep and go Hügel style with about 18" of soil on top total to the same height but I was afraid of the settling causing the tree to drop to deep. As I mentioned before, I’m an overthinker and I even though about about leaving a 8" pillar in the center un touched to support the tree and prevent sinking to allow the Hügel “Mote” to work like the standard bed would but still thinking. My thought there is that while the Perimeter of the “Mote” would settle, the tree itself would stay above and I can backfill the settling soil with local dirt etc to maintain uniformity.

I’ve even gone so far as to use a cheap 18" long, 1/2" diameter drill bit to drill in the bottom of my Hugelkultur raised veggie beds to “Aerate” and allow drainage in my garden beds which are already a total depth of 36-42" (30" into.the soil and a 12" raised bed on top) because I’m nuts and hoped it would improve drainage. I sprinkled some (1/4-1/2 cup total) worm casting and Bone meal on the bottom and into those holes as well to help with any Nitrogen leeching. Haha. Overkill probably, but like you said, plan for the worst (within reason) and not have to wish or realize you should have.

Again, Thank you for your time sharing your experience on this. I’m still quite new to all of this.

-Jimmy (AngelOreo)

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I feel like the “don’t amend the planting hole” advice is mainly to avoid people overdoing it. Having anything more than maybe 1/3 amendments can maybe theoretically create a “bathtub” effect, or a situation where plant roots won’t leave the planting hole in certain circumstances, although I’ve never experienced that.

I do amend, but if possible, I amend a very large area. My fruit trees are planted on the same plot that was originally tilled under, limed, and amended with compost for all my food crops, so their entire future root system is likely to remain within those bounds.

However, I do amend the hole for ornamental plants as well. Granted, my soil is already pretty well drained for the most part (except some areas near the house where the backfill/grading was a much heavier silty clay). I’m amending mostly due to pH and low organic matter, not drainage.

Example. I just planted an ornamental weeping Higan cherry. I actually got out the tiller, turned under about an 8’ wide circle, and turned in about an inch of compost. Then as I dug the hole, I mixed the soil from the hole (since I dug about 7" deeper than the “till line”) as well. Yeah, I know within 2 or 3 years, the tree will have rooted beyond that point, but I’ve found it does make a difference in the first couple years’ growth and establishment.

However, I don’t “overdo” it. Just 1-2" deep compost turned in over a fairly large circle is all I do.

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Great info. Thank you.

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