Blueberries and Battery Acid Adventures

After adding a cup of battery acid to 20 gallons of soil earlier in the week, my soil ph now reads 6. Still too high for blueberries but I now have new growth! I think I if I just use PH4.5 water for this season all will be well.

I probably should have let the soil settle for a few days before repotting to ensure a more stable ph.


I would call myself an impatient blueberry grower. A large majority of the websites suggest amending your soil and adding sulfur if you need to lower pH and then waiting for a season to give the bacteria a chance to convert the sulfur to sulfuric acid. I have always been impatient and planted in the same season. The result has been that I have had to treat with chelated iron in the first season to combat chlorisis. I have also irrigated with vinegar water mixtures, but I think that the foliar application of chelated iron was more important. I strongly suspect that with a little extra care your blueberries can survive a season at pH 6. By the 2nd season my soil pH typically dropped to < 5.5 and the extra iron is not needed. Hopefully yours will do fine.


Adjusting your water to the low end of your desired pH is a great idea. Once you overcome the buffers, your pH will drop faster. It is good not to water at too low a pH for that reason.

1 Like

Just came across this interesting blueberry article, while looking up blackberries.

I hope someone finds it useful. It seems like I find more useful information when I am searching for something else. I feel like Google search results have become far les relevant in the last few years.


174 pages! Very useful.


While some sulfur is good, phosphorus is a more widely utilized nutritional element for most plants (the P in N-P-K fertilizer % listings). This is why you will find so many commercially available PH Down products are Phosphoric Acid.

1 Like

PRO TIP: Starbucks provides used coffee grounds for free through corporate wide grounds for gardeners program. Call ahead to be sure they are saving. TEST PH as not all batches are equal blends. Mine tends to run 5.5.


Coffee grounds are overrated. 5.5 is not particularly acidic on a stand-alone basis.

They have been ground up and then steeped in near-boiling water, which of course, goes into our gullet. By the time they get incorporated into the soil there’s not much there.

It does make the soil look great. There’s no denying that.


I would suggest going to the swimming pool supply aisle and getting pH reducing chemicals there

This thread makes me thankful for my naturally-acid soil!


My soil comes in at PH 7.8

Be on the look out for morels at that alkalinity

If nothing else, that makes for a good free organic addition to any soil mix. Thank you for the tip!

1 Like

Pools tend to use Muriatic Acid (this is dilute Hydrochloric acid). Many plants don’t like Chlorine, Miracle Fruit being one as I understand it.

Last year I learn all about growing Blueberries, now I have to learn about battery acid. My little plants has grown pretty good this spring, nothing last year. I,ll stay what I have learn last year, no more, especially battery acid, forget about that stuff.

What makes sulfuric acid or sulfur the best to use is that sulfuric acid converts carbonates to gypsum. Which is stable and neutral in pH. Vinegar is soon neutralized by bacteria and does not remove carbonates at all Same with citric acid. As carbonates build up you will need more and more of these acids to get to the right pH. Sulfuric acid removes them from ever interfering again.


great for loosening up my clay soil and the worms go nuts for them. = win/win.

My last batch I stopped by late Sunday morning and asked them to collect while I ran errands. 2.5 hrs later 15 lbs mostly dark roast with ~15-20% dark roasted WHOLE BEANS. Not the norm to get whole beens but they are always sooo happy to see me. Haven’t made request for dark roast before but will start now. When’s the last time you tested TDS on used grounds? New? Compare to commercial azalea mix if U have near good soil. If not perhaps its better to make good soil first and transplant?
What is PH of your moss?

Trying my hand first time miracle fruit for which coffee of all kinds is useless, so matter of perspective I guess. I reserve Sulfuric acid for scarification and do not recommend for those new to handling such as it is used in concentrated form this purpose. Anyone have optimal nutritional requirement info for Blues, Rubus, or Miracle Fruit? If so bring it. New topic?

Can U say free?