Don't add additional organic matter to the planting hole. Just use your normal soil. Add organic matter to the top as a mulch.

Rain2Fall

I agree with the quoted information you have posted. No one knows what your soil may be like and you may need to "subsoil" the area to breakup a severe compaction problem as was suggested. Nothing was mentioned about mulching, but a regularly maintained vegetative mulch four or more inches deep will help a lot to relieve a soil prone to compaction. Al

It really depends a lot on your local conditions. Where I live our soil is compacted pulverized granite. You can't drive a steal stake into the ground with a sledge hammer. To dig a hole you rent a demolition hammer with a spade bit or you use a heavy pick or pickax and it takes forever. Here we dig a hole and plant trees in a mix of 50% native soil and 50% composted organic material.

When I lived in Northern California you could just dug a hole with a shovel and planted the tree without any soil additives.

To me the additives are more to loosen the soil for root development. You still have to top dress them with composted material every spring as a fertilizer.

I was taught that tree roots are pretty stupid, and if they're planted in a "luxury" hole they will act as if they were in a big pot and eventually before pot-bound. Their roots will fail to penetrate outside the hole.

And in fact we were also taught to make the sides of the holes ragged, so the hole is circular overall but not smooth. And by the same token amendments were generally discouraged, but mulching was encouraged.

marknmt that thinking is entirely right unless your soil is not conducive to the survival of the tree or plant and needs space to get established.

A few examples would be....

Damp heavy clay or adobe. Then you may want a raised bed with plenty of amendments.

Another example is the hard as rock compacted granite where I live. Here we dig a hole a bit deeper than the depth we want to plant and add 50% native and 50% amendments.

I have been told many times the better way to go here is to have the entire garden/orchard area amended down 24"-30" so the roots can really grow without running into the harsh native soil conditions.
This does not create the container/bowl type phenomenon others have mentioned and makes for ideal growing conditions where none existed before.

It's hard to really know how if you don't know why. The different answers above show that the reason for confusion is that there is no single answer for all conditions-as was stated.

If the soil is too compacted for root penetration creating a pit will obviously trap water during rain and hold it- where can it go?

Even beyond this extreme situation a "luxury pit" (not a term I've heard used in the U.S.)suggests a pit with soil of a different texture than surrounding soil. Due to cappillary pull, fine soil draws water from coarse soil so contrasting textures between pit and surroundings will either lead to droughty or excessively wet conditions if there are contrasting textures. This is why dumping amendments in a planting hole is sometimes injurious.

I agree with thisisme and would also suggest that very few home orchards employ a sub-soiler or install tiles so the rased bed approach is usually the way to go where it's needed.

Hi Thisisme.

I'm in full agreement with you, and thanks for making the distinction. Yes, there are situations where you simply can't overdo amendments, and where native conditions are so hostile that almost anything you do will be an improvement.

I'm starting to feel grateful that all I have to deal with is my thin topsoil on an ancient riverbed. We go down about six inches and hit rocky/sandy/clay, so sometimes you feel like it's all hydroponics.

Best,

M

Use no soil amendments except in very specific conditions of raised or amended beds for plants with very limited root systems. If the existing soil is very poor, remove and replace with good field soil or place at least six inches of good field soil on the surface. However, you should match soil types as backfilling with a good sandy loam in a heavy clay will serve as a collection point for water and the roots will suffocate. Soil amendments in a small planting hole do not assist plant establishment and growth...It is better to use the amendments as a mulch. The only exception is where the entire plant root zone for many years can be amended

--Whitcomb, Establishment and Maintenance of Landscape Plants (1987 (1991), Lacebark Inc., Stillwater)

Here is a link that might be useful: Establishment and Maintenance of Landscape Plants II

Actually Whitcomb is contradicting himself in the statement about backfilling with a good sandy loam. A coarser soil will have the moisture wicked from it by a finer soil as he explains in the same book. I read that book about 20 years ago and still refer to it. I assume he is referring to the lack of drainage created by a clay soil. Otherwise- if the water could drain down, say because the backfill went beneath the impervious layer, the finer soil around it would make it difficult to keep the coarser soil moist.

Carl is a master of plant container engineering and he's been responsible for a lot of research that blows horticultural orthodoxy out of the water but there are no absolute answers that will replace actually doing some of your own thinking and adapting to the specifics of your own site.

If you can grow a semi-dwarf fruit tree in a 50 gallon container you can certainly grow it in amended soil if the native soil sucks, as long as you can provide drainage and adequate moisture.

It looks like drainage and soil amendment has been covered pretty well by the previous posters, but, since there are also other issues involved (when to plant, checking the site, examining the plant before planting, etc), I will attach a link that attempts to cover all the basics involved with planting a tree.

Here is a link that might be useful: Planting a Tree

brandon7, Thanks for the link. I'll be planting lots of potted trees soon, so I was wondering what to do if they are rootbound.

So far no one has mentioned using root hormone. I was planning to buy some and put it in the holes I dig. Any comments on this stuff?

Here is a link that might be useful: MYCORRHIZAE PRODUCTS

Much better for the bottom line of the company that sells it than for your trees.

I second that motion. Brandon 7 and I are actually in snyc!

I have appreciated a lot all your sdvice and tip , I think
the link posted by Brandon7 is the base I will follow.
To tell the truth I already had some similar ideas , I wanted to clear my mind . for this reason I posted on this US Forum ; I always use to explore.

I always really appreciate a lot American way to approach things and I have not been disappointed this too.

I would like to recall with you when my father and I planted several trees that needed too many years to start to grow well !

This time I have no so much time to wait for,my late daddy would agree too.

Thanks to all from Tuscany .

Orto, you are a true goodwill ambassador from Tuscany. Thanks for making my day with your positive message.

Along the same lines as this thread---

So what do those supporting the "no luxury pits, no organic amendments" propose gets added to clay soil to help with drainage? Sand? I always add Gypsum, but that's certainly not a drainage solution.

My local nurseries only have rice hull mix (with "som nitrogen and composted wood shavings"). This is the only suggestion they have to amend clay soil to help drainage.

Thanks

So re-reading it again:

For clay soils, just "till" it deep in late summer removing large stones if there (or in my case very large roots from neighbor trees). Add slow release fert. I assume they support drilling the drainage chimneys suggested by Univ. of AZ Ext. on each side of a planting.

They are basically forcing the raised bed route with these directions for trees/stocks that are drainage sensitive. And if a particular planting needed a lot of drainage -- they'd say don't plant it?

An alternative: Create a interim layer 12" thick between the old sub-soil and the raised bed with a 50% mix of each. This would allow at least SOME possibility of avoiding soil "layering" of extreme texture differences and give some roots the chance to grow into the interim layer.

How does that sound?

It's what I do and has worked for me over the years.

I dig my hole double or more. My soil is tough clay. I usually break it up screen the clay 1/2" and then add some sand and maybe 10% peat or bark and some plantone.

If soil is really heavy clay or wet ground, I drill lots of holes in the bottom of the hole for drainage. This hole was not too bad for clay but was in an area that gets lots of water pooling in heavy downpours

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Don't know if this is the best way, but that is how I am doing it. Can't imagine just putting the clay back as is. It is huge clumps sometimes near a foot long.

Quite a nice bit on that -- hammer drill? When I first started doing gardening here, I spent $100 (with discounts and coupons) on the lowest quality Harbor Freight demolition hammer (like a mini jack hammer, but can be hand held). It acts a little funny (won't engage easily sometimes) but I've put many hours on that thing and it was WELL worth it as renting one would've been $70 for the day. It tears apart the rock-hard hard pan. My hard pan cannot be broken with a pick axe; the first time I tried was hilarious. I had padded gloves, safety gear, lifted the axe overhead and let loose a full-body powered swing onto the pan (I love to chop wood and I've broken up sidewalk with a sledge and pick, so I know how to "power chop"). Well, my attempt was less than successful as there was a loud CLANG and with it a giant spark! The smallest little dent was made the size of a dime. My boys laughed as I put the axe down and tried to get feeling back into my still vibrating hands for the next couple minutes. Felt like I was in a Looney Tune cartoon.

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This picture is a section that was breaking off in chunks. The piece in my hand it turned over -- the pan to the right of my hand is more typical.