That's an interesting idea and worth trying.It could give a head start for next year.
Will this be going in pots?I,myself use Pine bark mulch and Peat moss,especially in containers.That way,it breathes easier.
I wonder if burlap sacks will work.
I'm not sure if heat will be a detriment.
Thirty liters equals about seven gallons.So maybe about a half cup.Amounts could be experimented with and if too acidic,then more medium could be mixed in. Brady

Cups of S per 30 liters is vastly excessive. Neither I nor anyone else can tell you what would be right. We'd need an analysis of the soil which you can get from a soil testing lab.

But you don't need months or elemental sulfur. If you use sulfuric acid and have a good pH meter you can cut out the middle man, the microbes, and adjust the pH in a couple days independent of soil temperature.

I'll tell you from experience it's easy to over acidify. If you do use alkaline well water to raise pH. I use battery acid, I think it's 33% sulfuric, and much safer than the 98% stuff.

If you start with the right media it takes little or no acidification. That's my recommendation.

fruitnut,

I have a bottle of Phosphoric Acid 17% (used for hydroponics). I mixed it with rainwater (not tap water) and lowered the ph to somewhere between 4-5. My blueberry plants seemed to like it. Some of red leaves turned green, and many new canes popped up. However, the pH of the soil stayed the same. I only did this once (last week).

If I do this more frequently, do you think I can easily lower the pH of the soil, or does it only work with sulfuric acid? Wouldn't it cause an overdose of phosphorus? Would it be harmful to the plant?

This post was edited by Ghadames on Thu, Jul 3, 14 at 12:33

The microbes would indeed need air (oxygen) to oxidize the sulfur to make the acid.

The blueberry source I deal with recommends a potting soil of 3/4 Sphagnum "peat moss" (actually moss peat) and 1/4 perlite, for which no "curing" time is needed as the peat is already acidic.

I won't use P acid long term. Too much P can interfere with uptake of other nutrients. Sulfuric is the ticket for acidifying soil or water IMO.

Thanks, gonebananas.

fruitnut,

Do you know if it would be ok to use vinegar instead? Would it have the same effect as phosphoric acid?

I know vinegar is a temporary solution, but I'd like to water the plants with a mix vinegar and rainwater (since I have plenty in storage). Could it cause any problems in the long run? I would only do this for the rest of the summer while waiting for sulfur to have an effect on the ph.

Instead of creating another thread, can you guys have a look at this picture, and tell me if the yellowing of the stems of my blueberry plants is some sort of fungus or something else? Is it something serious? The leaves look fine.

Do the stems pictured belong to a Jersey Blueberry? Brady

No, Northland. I saw some on my Patriot, too.

With rainwater you don't need vinegar if media pH is low enough. If not low enough that sounds like a reasonable path of action.

I'd say those stems are OK. It could be an issue but some of mine are moddled and I haven't had any related issues that I'm aware of other than thrips. Don't think that looks like thrips damage.

I just bought a bottle of "pH Down" for aquariums. It contains sulphuric acid 9.6%. Do you guys know if I can use this as an alternative to battery acid? I would mix it with rainwater.

There's no list of ingredients on the bottle, so I'm assuming it contains only sulphuric acid and water? The liquid is clear. Surely if it's safe for fishes, it can't harm blueberry plants.

What do you guys think?

This is the actual product:
http://www.apifishcare.com/product.php?id=644#.U73x-rEuf-J

It's fine to use, but depending on your water, what PH is, how many carbonates need to be neutralized, the amount needed can only be determined by a PH test of the water. Too much can certainly harm your plants.
Battery acid is 33%, it lasts longer. I use a PH meter. I like the ones with no batteries, but you have to clean probe every time. I use steel wool.

Yes, I have pH strips. When you say battery acid lasting longer, you mean the acid would take more time to expire? I didn't know acids had an expiration date. On the bottle I have, it is stated that it expires in July 2018.

If I have a soil ph of 7 and if I want to reduce it to a ph of 5, what should the ph of my solution be? And how frequently should I apply it to my plants? I've also added elemental sulfur, so I'll have to monitor the ph constantly.

This post was edited by Ghadames on Wed, Jul 9, 14 at 23:55

Sorry bad choice of words. I only meant battery acid will last as you use less of it since it is concentrated.
Plus it's not expensive, any auto parts store will have it.
The product you bought is probably more expensive. You have it now, and it will work, but when you need more I would go for the more concentrated and cheaper battery acid. It's safe to use, often suggested by universities. Law requires it to be only sulfuric acid and water, else one will mess up batteries! It's an excellent safe product.
Since it may change PH quickly I would use it at 5.0.
The PH may rise but I would not use a lower amount. Just keep using it at every watering. Once your soil is good you can use less, or none at all.
I have found with compost soil tends to want to rise, so even if you get it to 5.5 or lower, it will eventually rise again. So monitor it. Hard to figure out soil PH at times. My meter works better on liquids. I wet soil then test.
In ground last year I got the soil to 5.0 or a little lower. this spring the soil was at 6.5! i was shocked it changed that much over winter. And i use sulfur in the soil too!
So I use elemental sulfur and use sulfuric acid at 5.0 every watering from now on. Sometimes when in a hurry I don't use it, but I always use rainwater.
I ran out of acid last week, today I just used rainwater straight. My rainwater is 7.0, it's not really acidic. It's pretty clean, and for living in Detroit, it's impressive!
A side effect to clean air, no acidic rainwater!
I'm going to O'Reilly's tomorrow for more.

Yeah Ghadames,I started out with vinegar and progressed to something like pH Down,a product for spas that was about 10% Sulfuric acid.That was about $7 for 16oz.So now,I use the battery acid.Less money.Brady

My rainwater is around 7, too, and I live in Montreal.

I read online about battery acid. Is it really pure diluted sulfuric acid? I read that it may contain "lead" and other elements that may be harmful to plants. Are those just myths or is there some truth to them?

Total myth.I find your comment very amusing. As if what you suggest were true, it would ruin the battery. Sulfuric acid will not dissolve lead, it would have to be added. Pretty sure that would ruin your lead-acid battery. Besides the fact the battery may explode. Always use distilled water and battery acid only in lead-acid batteries.
You know I have a golf cart, long story, I use it every weekend. I have 6 lead-acid batteries in it.

This post was edited by Drew51 on Thu, Jul 10, 14 at 1:43

Okay! For a newbie, that's some serious comment! :P There were so many of these comments online about not using battery acid for plants, others saying it's fine. It got confusing!

Understood, it is confusing and not asking is stupid, no question is stupid, it was a good question! Really impurities in acid could cause batteries to explode, it must be pure acid. US law regulates grades of acid. I believe three grades exist. The lowest grade does have impurities, and is used to make fertilizer.
I was a med tech and often worked with very dangerous pathogens, like HIV virus, so to me it's not a big deal working with acid. I forget that most don't have my training. It is very dangerous, and you should use what you feel safe with.
Pure sulfuric acid is interesting, it's syrup like, even I don't mess with that. Although users here do use it.
If you spill battery acid on your hands, you can wash it off with no burn, but you should use gloves (and eye protection for sure). I use surgical gloves myself. I used to wear them all the time at work. I'm used to wearing them. I know how to remove them with contaminating myself. Safe enough for a weak acid. I like using the gloves when applying pesticides too. You just throw them out, less chance of contamination.

This post was edited by Drew51 on Thu, Jul 10, 14 at 1:46

I have 24 blueberry plants that struggled last year to grow and produced almost nothing. After doing 3 things, all of them now are thriving and are producing blueberries.

Those three things that made a difference:
1) Sprayed all of the plants with lime-sulfur while dormant to kill of fungal diseases;
2) Fixed the drainage problems that left the plants sitting in puddles of water; and
3) Used a product called Encap Fast Acting Sulfur (link below)

This sulfur mix was purchased through Home Depot and started showing results within 30 days. My blueberry plants have stayed dark green all year and have nearly doubled in size after not growing at all the previous year. This sulfur comes in a 20lb bag and you don't need much for each plant. This made a big difference.

I planted my blueberries in soil amended with peat moss and pine bark.

Getting blueberries to grow seemed daunting last year, but you can do it. Don't give up.

Here is a link that might be useful: Encap Fast Acting Sulfur

Thanks, jtburton. I'm no expert, but I think the reason why your plants weren't growing was probably because the pH of the soil was too high, a problem that I've always had.

I've never seen a lime-sulfur fungicide in stores. I have a sulfur based fungicide. Would that still be good? How many times did you spray them while dormant?

I haven't seen Encap Fast Acting Sulfur in stores. But according to fruitnut, mixing sulfuric acid with tap water will permanently lower the soil ph and much faster. I used the sulfuric acid based product today and mixed it with rainwater. Despite all the danger warnings I read online, everything went fine and felt pretty safe!

This post was edited by Ghadames on Thu, Jul 10, 14 at 23:17

"Permanently" is a relative term here because the pH around your blueberry plants will go back up again....it is more of a question about "how long" will it stay low. In my blueberry location, the surrounding soil leaches away other pH corrective measures quickly. The only thing I have tried to date that has lasted, and worked, has be the elemental sulfur in the "Encap Fast Acting" brand. I have used it twice this year and so far almost every plant has finally started growing like it should and doubled in size. There are a couple of plants that may need a third treatment before the Fall.

As for lime-sulfur, it is generally only available at Ag stores. I sprayed the blueberries once and that has lasted (e.g. prevented leaf spot) until recently. I'm seeing it return somewhat but this has been a very wet season.