Coming from a hard core alkaline region, I'm conditioned to say that pH rules over all other conditions. If you test only one little thing, test pH.

Saying that, you couldn't possibly have removed ALL the soil from an area. You worked only the surface (guessing!) and now you want to plant a tree with roots far more extensive, eventually, than those of a little fruit bush. I usually claim that preparing a tree hole is a waste of time and energy but in this case it could be worth it if only for the peace of mind it could bring. Go with your idea to replace the conditioned soil in a small spot with "ordinary" dirt and plant the tree there.

It will grow beyond the puny attempts of mankind to tell it what to do!

If you modify the soil for a tree, it's wise to do the entire planting bed, never just the planing hole. But realize that the pH will eventually return to what is normal for the region.

Rather than try to fix an "extreme-ish" pH, it is far better to plant a tree adapted to the pH of the native soil.

You need a good reliable soil test for soil pH and major nutrients as well as amount of organic matter in the soil. In your area of the world, with the low rainfall you normally get, your soils pH will be alkaline.
A native tree, one adapted to your area a good idea.

Those pH tests from the retail nurseries are a waste of money.

You most likely did nothing to acidify the soil if all you added was some 'acid mix' potting mix. Did you nursery recommend that to you?

you don't need a test, just find out what grows well in your neighborhood. that soil is back to where it was. if in doubt, add organic matter.

These are the instructions from my high end nursery and a Master Gardener friend of 25 years. As advised I used an acid planting mix.

I was wrong in my original post, I didn't remove ALL my soil but followed the instructions.

I did not use Soil Sulfur but rather cottonseed meal for the 3x a year fertilizing.

I am gathering from everyone that my soil most likely is not acid anymore.

Thanks for your input.

Here is a link that might be useful: Blueberry Planting Guide

If you didn't use sulfur, your soil was probably never acidic.

Southern California soils tend to be alkaline (sodic) because of the low rainfall. To determine what the soil pH of your soil is you need to have a good reliable soil test done, one that will advise you on what you need to do to get that soil pH where you want it. A soil test kit from a garden shop may tell you that the soils pH is X but provides no information about how much of what is needed to change that pH.

Lot of misinformation going on here....:-)) Acid planting mix can certainly help to achieve a proper degree of soil pH for some plants but it is unlikely to be a permanent condition if you use it in an inground planting situations - much more effective long-term if used in a raised bed or in a container situation. 8-10 years is a long time so I'd guess that current soil pH is no longer very acidic but you will not know for sure unless you test.

And retail soil pH test kits are NOT worthless.....in fact, they are about the only accurate soil test kits there are on the retail market but you must use them with distilled (not tap) water. SoCal soils are often on the alkaline end of things but that is very different from sodic - if you have concerns about that then a professional soil test is advised.

And finally, most plants are adaptable to a range of soil pH so that does not necessarily limit what you can plant in your existing soil conditions. Just avoid those that prefer the quite acidic conditions like the blueberries. Many fruit trees grow very well in SoCal soils so check and see what neighbors might be growing or what's sold at your local nursery.

More mis-information in previous post; the bit about pH & sodic soil.

Alkaline soil is sodic only if it contains excess sodium. An unlikely event in SoCA, even if the garden is beach-side.

Jean,
who gardened in Long Beach, CA, for 30-some years and who taught Ornamental Horticulture in a local college for 15 of those years, including Soils classes.

Those pH test kits might be the most accurate test in a retail nursery but that doesn't mean they are worth a damn. The regents have typically been sitting around forever and the colors can get swamped out by the soil pigments rendering an accurate reading a crap shoot. Plus for the price, considering they will absolutely be expired by the next season and so you'll only get one or two tests out of them, you might as well send a sample off to a lab.

Now if you want to invest in a proper pH meter from a hydro store with calibration solutions, that's a whole other story.

jean, unless I am mistaking the intent of your last post, I think we are saying the same thing :-)

Technically, alkaline soil by definition IS sodic, sodium being part of the alkali metal group of elements that offers this soil type its label. I (and a whole bunch of other folks) tend to refer to any soil with a pH higher than 7 as alkaline regardless of sodium content when the proper or more accurate terminology should be 'basic'. As it is stated "alkaline soils are basic, but not all basic soils are alkaline". But it seems the most common terminology used with respect to high pH soils is 'alkaline' rather than 'basic' regardless of the sodic content.

nil, those retail test kits, when used as directed with distilled water, provide remarkably accurate results the vast majority of the time.

(gardengal48, who also teaches soil science for horticulturists and Master Gardener classes)

I meant in "a" previous post. So, correct, not your post.