I haven't done what you suggest because bb grow so well in pots. But if you manage properly this should work. If you need to irrigate, pH of the well water will be a concern. On that big of a planting hole I won't think the surrounding soil would have much effect. You will probably need to add sulfur or other acidifiers to the planting area and do a good job monitoring pH.

It would help if we knew where you are located. It's my impression that rainfall is more acidic further east. That could have some affect.

I think it can be done with the knowledge you will always have to maintain the ph. I would dig the hole and fill it with water adding one cup of white vinegar to acidify the immediate surrounding soil. After the water drains I would add one cup of granular sulfur and one cup granular Ironite sprinkled evenly in the hole.

After planting I would also topdress with granulated sulfur and one cup granular Ironite before adding the mulch. Remember to topdress with granulated garden sulfur every spring. If the ph drifts to high you can always add a couple tablespoons of white vinegar per gallon when you water to correct it.

Our local soil is fairly high in clay, and has pH = 7.6, due to the limestone found around here, I suspect. When planting blueberry shrubs, I dig a hole similar in dimensions to the original post, and then I put 6 ounces by volume of agricultural sulfur in the bottom. Next, I back fill 1/2 way with compost(made from shredded Norway maple leaves), add some dirt, mix the two thoroughly, and plant the shrub. Finally, I add another 6 ounces by volume of agricultural sulfur around the the hole, to a radius of 16 or 18 inches, and mulch with shredded tree leaves, to a depth of about 6 inches. The shrub is immediately watered in with 4 gallons of tap water, to which 6 fluid ounces of 5% white vinegar(from the grocery store) has been added. This planting method works with our soil, it is not universal.

Hey Eric and thisisme, I'm wondering if you could kindly provide something to back up the recommendations of vinegar. This has been discussed before and the real chemists say that vinegar has no permanent effect on soil pH.

Vinegar ties up the Ca and Mg cations, the bad guys, in an organic compound. Once the soil bacteria break down the organic part of that compound, the Ca and Mg will be free again to raise soil pH back to where it was to start with. So vinegar has only a temporary effect on lowering soil pH.

No the other hand the material I use, sulfuric acid ties up Ca as gypsum. Gypsum is neutral in pH and stable. So by tying up CA as gypsum the pH is permanently lowered.

Sulfuric acid is used commercially by blueberry growers to lower pH on large fields. The effect is very rapid and permanent. I buy battery acid which is 33% sulfuric. The stuff can be dangerous but with care is safe to use.

What say ye all?

>I would dig the hole and fill it with water adding one cup
>of white vinegar to acidify the immediate surrounding soil.
>After the water drains I would add one cup of granular
>sulfur and one cup granular Ironite sprinkled
>evenly in the hole.

I'm not sure if this is what you meant, but it sounds like you're recommending putting sulfur in the bottom of the hole. To adjust the pH of the root zone, it would be more effective to put the sulfur above the roots, at the surface and covered with mulch, or scratched in a bit. Sulfur lowers soil pH because bacteria metabolize it into sulfuric acid. The acid will diffuse some, but I think the dominant spreading action will come from rain washing through the soil. What I'm getting at is that very little of the sulfuric acid formed at the bottom of the planting hole will make it up into the bulk of the root zone.

Of course, for the initial planting, mixing it in with the soil would be good as well.

Alex

You have to lower the ph or the blueberries will quickly die.

alaxendar3 if you read my post you would see that I also recommended topdressing with soil sulfur at the time of planting and yearly.

fruitnut whoever said White Vinegar is permanent solution? I am saying that White Vinegar is a easy to find immediate temporary, cheap and safe way to lower ph while you wait for sulfur to work. I never said it would permanently reduce the soil ph? I said it immediately lowers the soil ph and that sulfur was needed to maintain the ph and that White Vinegar can always be used as a quick temporary fix is the Sulfur is a little slow to work.

Are you saying that Sulfuric Acid is a permanent solution? That once applied it will never wash away or dilute?

There is more than White Vinegar at work here. The is Peat which is low in ph. There is also Sulfur. The Sulfur will produce Sulfuric Acid slowly as a byproduct of its interaction with soil bacteria. An application of sulfur in the hole and a once yearly topdressing of Sulfur is necessary in order to maintain soil ph.

Below is a link to an article published by Michigan State University Extension. Michigan is a blueberry producing state and they know what they are talking about. It may help explain the use of soil sulfur and how sulfuric acid is created as a byproduct of its interaction with soil bacteria.

Here is a link that might be useful: Lowering the Soil pH with Sulfur

ericwi, I have lots of clay in my soil oversees in Europe too...it is also VERY HIGH in calcium. For us that would mean Iron is less available.

My experience has been that vinegar added to tap water, for blueberry irrigation, has only a temporary effect on soil pH. The pH will drop, but it will rise eventually, in a matter of months. There are three advantages to using white vinegar for this purpose. Since it comes from the grocery store, it is food grade, and you don't have to wonder about purity. For people who are nervous about using chemicals of any kind in the garden, 5% white vinegar is less threatening, since it is exactly the same material used for making salad dressing or pickles. The third issue is storage of unused material. A half-full jug of 5% white vinegar sitting in the shed, or in the garage, is not much of a threat to anyone, including curious children. I have no objection to the use of sulfuric acid for lowering soil pH. It must be done with care-too much acid will kill very effectively.

Using sulfuric acid is the same as applying sulfur only it acts in a matter of hours or days rather than months or years. And it is permanent in the sense that the Ca tied up in calcium sulfate, gypsum, no longer affects the plants. Whereas the Ca tied up by vinegar is back in the system in a matter of months.

All soils have a buffering capacity so after treatment the soil to some extent returns to it's original state. But the Ca tied up by sulfur is out of the system and the soil has been permanently altered. The same can't be said for vinegar.

thisisme and eric: Thank you for your clarification. As long as the effect of vinegar is recognized as temporary, then I think we are leading growers in the right direction. I can see where vinegar may have a place as a temporary acidifier until sulfur kicks in.