Ajusting potted blueberry pH with sulfuric acid and well water

13 years ago

Today in the space of 10 hrs we adjusted our blueberry media from a starting pH of 6.8 to 3.8 with sulfuric acid and back to 4.7 with alkaline well water. This is so easy I don't see the need for anything else to get off to a good start with potted blueberries.

Store bought battery acid is 33% sulfuric acid. I dilute it by pouring one qt into 9 qt water. This gives a stock solution that is 3.3% sulfuric and makes it much safer to handle.

It took about two qts of the stock solution mixed in a couple gallons of water leached thru ~12 gallons of potting mix to lower pH to 3.8. Had we been more careful we could have stopped at 4.5 to 5. But having gotten to 3.8 we leached with alkaline well water three times to get back to 4.7.

We'll wait a couple days to see if the pH is stable before using the mix.

We earlier adjusted from 6.8 to 4.4 after planting with excellent results. We used well water adjusted to ~ 3.5 pH to do that.

Sort by:Oldest

Comments (4)

mr.ed
13 years ago
The problem with that is, battery acid is not refined, and may contain contaminants such as mercury or lead. It may not enter the plant, but the runoff may pose a mild danger.

You are also tweaking a high PH soil and assuming it will stay that way...it will not. Most revert back towards their original PH on the basis of their makeup. ExampleÂpure peat fertilized with plain miracle grow will test at a higher PH, but will soon revert back.

Better to start with a material close to the desired PH or you will be forced to constantly adjust as commercial blueberry growers do. The reason they choose this method is financial, easier to tweak, rather than remove and replace yards of earth, while on a smaller scale the opposite is often true.
fruitnut Z7 4500ft SW TX
Original Author
13 years ago
Thanks for the heads up about possible heavy metals in battery acid. That was in the back of my mind. I'll buy some technical grade sulfuric acid to solve that issue. Heavy metals can also be in dry fertilizers like Ironite.

As to reversion of pH. I know that will happen to some extent. But it's not something that concerns me. And it happens with any method of adjusting pH. Just monitor pH and adjust again.
Related Discussions
Please help! blueberry soil pH is 7.1 - need to plant this week
Q
Comments (41)
This will give you an idea of how my plants have done Appletree. This is two years after planting a 10 inch start. I'm not sure there is a "best way" to grow blues, even experts have a wide range on what's "best". Some say only pots, others say ammending the soil with sulfur and wait for ph to adjust, others add peat and pine, etc. I have been growing blues for about 8 years and have tried several approaches, most worked. The one big mistake I made was buying some older plants and I never could get most to grow. The best luck I have had has been with healthy young plants. Your plants are gonna do great. Did you say you are a biologist? I am too and that's why I asked. This post was edited by riverman1 on Fri, Apr 4, 14 at 11:03
...See More
Red Blueberry Leaves, pH Test Inconclusive
Q
Comments (12)
Here in Madison, Wisconsin, we have alkaline clay soil, with a pH around 7.6, so I have to use sulfur to get the soil acidic enough for our blueberries. I have used several methods for checking soil pH over the past 20 years, including a pH meter, pH paper, and dye indicator solutions. They all work, but dye indicator solutions give clear results, and they don't require any calibration step. You can get a small bottle of bromocresol green indicator for about 4 dollars, mail order, from HMS Beagle. I'm sure there are other sources. It will take a year or two for soil bacteria to metabolize the sulfur in your blueberry beds, so it is not possible for the sulfur to be causing the discolored leaves. When blueberry shrubs are transplanted, the root system is disturbed, and it takes the plant a month or two recover. For this reason, it is best to plant them in the early spring, just after the ground thaws, and before the shrubs have leafed out. But I think your shrubs will recover and do fine. If you see some sign of burning leaves, or browning leaves, it helps to cobble together some sort of shade, and protect the shrub from the worst of the mid-day sun. Too much nitrogen fertilizer will cause burned leaves. You will have to find out the pH of your irrigation water, unless you know for sure that you have soft water, free of dissolved limestone. If you have hard water, that will tend to raise the pH of your blueberry bed, and counteract the sulfur that was added to the soil. My tests have shown that blueberries will grow over a wide pH range, from 4 to 6.5. They grow best at pH in the range 4.3 to 4.8. I was under the impression that New Hampshire had naturally acidic soil, and if that is true, the soil pH in your blueberry bed might eventually get too low. But this will take several months to develop, and by that time you should have been able to get a handle on pH measurement, and be able to see what is happening. The method I use for pH testing is to mix a tablespoon of dirt with enough distilled water to make a slurry, and filter this solution with a clean paper coffee filter/funnel. A teaspoon of filtrate is plenty enough for testing. Add just enough bromocresol green indicator to see some color. Green means the pH is between 4.3 and 4.8, blue indicates the pH is around 5.4, and yellow indicates the pH is around 3.8. There are other indicator solutions available that can be used to see other regions of the pH range.
...See More
Will Miracid actually lower soil pH for blueberries
Q
Comments (8)
Thanks to all. I have no concerns whatsoever about going the sulfuric acid route, particularly as I have a boxed bag of same sitting in the basement. To those who do the same, seems like I've seen a couple methods suggested on www searching, some do so at all watering with the pH of the water adjusted to a higher level (5.5-6.0), some do occasionally with pH adjusted down around 4.5-5.0. And then some suggest mag sulfate (epson salts) or vinegar instead with all watering. Anything optimal? Plants did have some yellow veining at beginning towards the end of their hardening stay and then first month or so after transplanted. Now all heavy green foliage, well being this is AK and all, now getting a hint of red, like I said maybe the Chippewa will have time, maybe not. My rock is granite mostly. The 35 year old AK log house foundation is get this pressure treated wood for the full basement. Who knows what is leaching from that, it is the old stuff with a lot of copper obviously and who knows what else, but the plants are about 8 feet out from the wall, I'm not too concerned. I'll go with the suggestion of bamboo_rabbit today and water all with water adjusted down to 4.5 or so. Thanks again.
...See More
How does well water with Rust affect pH?
Q
Comments (7)
Iron is a plant nutrient, but they don't need very much, so the rusty well water will likely supply more than the plant needs. If you are accumulating lime deposits on your teakettle, or having to clean up lime deposits around your faucets with an acidic cleaner, then you have hard water, and this will raise the soil pH around your blueberry shrubs, eventually. There are indicator dye solutions that can be used to check the pH of your well water, or you can have the water checked by a local lab.
...See More
olpea
13 years ago
Mr. Ed,

Do you have any references that store bought battery acid could have significant amounts Pb and Hg? I'm not trying to be contentious, just wondering if there are any reputable sources for the claim.

I bought some sulfuric acid to mix with water for irrigating the blueberry patch and would rather not add lead or mercury in significant amounts. However, I've noticed so many claims of this nature are based on internet hearsay and turn out to be false.

As an example, Fruitnut's mention of ironite is quite correct. It used to contain high levels of heavy metals. However, the company had such bad press and lawsuits they quit making it from mining tailings. Their product is now well under safety levels for any heavy metals.

Still, there are numerous websites warning people against the use of their dangerous product, which no longer exists.
mr.ed
13 years ago
fruitnut: no problem, I am not even sure if blueberries are able to uptake heavy metals. I know they are indifferent to aluminum. Was just wondering about the runoff from the potted plants.

About lead in IroniteÂyes I have heard that. I will not use it because of that fact. It might be safe for a lawn, but suppose next year you want to put a garden there, or use the clippings for mulch. Which leads me to olpeaÂs comment; yes most industrial grade agents contain some heavy metals and possible PBBÂect. Just how many PPM would depend on the manufacture, and with most industrial liquids made in China or Mexico where product safety is the last thing on their mindsÂÂah I would just pick up some sulfur as opposed to sending battery acid out for lab analysis.

I mean hey, I am feeding this stuff to my kids and eating it myself....so cost plays second fiddle, to safety IMHO.

Ajusting potted blueberry pH with sulfuric acid and well water

Comments (4)

mr.ed

fruitnut Z7 4500ft SW TX
Original Author

Related Discussions

olpea

mr.ed

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Ajusting potted blueberry pH with sulfuric acid and well water

Comments (4)

mr.ed

fruitnut Z7 4500ft SW TXOriginal Author

Related Discussions

olpea

mr.ed

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

fruitnut Z7 4500ft SW TX
Original Author