To answer your first question OH YEAH......too low is just as bad if not worse than too high. While from say PH 4 to PH 3 does not seem like much it is actually 10 times more acidic.

Your pics are not close up so is hard to tell but the bushes look ok. Are you sure your PH meter is accurate? Brew some strong black coffee and test the PH of the coffee, should be a 5. That would show if your meter is off.

Two cups seems like a awful lot of sulfur for a pot. The sulfur can take a year to react fully so is problematic to use.

If the PH is too low the plants look just like if it is too high. But like I said my first step would be to check the meter.

You can still use your grounds....while they are slightly acidic they won't change the PH enough to matter.

The ammonium sulfate will add a bit of acidity to the soil so is better to wait on that till you know if you have a problem.

If the PH meter is accurate you can just water the heck out of the bushes daily using well water. The bicarbonates in our hard water will help bring the PH up.

I brewed a strong cup of coffeee to check my Kelway. It started out at 5.9 and rose gradually over the next 15 min to 6.5, so if anything it reads high which make my low numbers look even worse.

When I potted these plants I avoided adding any garden lime to the mix knowing that they preferred an acidic soil.

Is it time to add a some garden lime? If so how much at a time and how frequently? I know now I need to stay on top of the ph.

PapaJim

Jim,

Are you sure you can measure liquid PH with your Kelway? I know with mine I can't do liquids.

I would not use lime ever on them. If you are on well water and you are sure the PH meter is accurate you can just water them really heavily daily for a few days and check again. The bicarbonates in our water are like liquid lime.

The thing that still bothers me though is if your meter is accurate and your ph really is lower than 3 your plants should be in distress.......since they are not it makes me wonder.

I am going to get my Kelway and measure the coffee grounds PH. Ok......I took my coffee grounds and mixed in just a bit of leftover coffee so the grounds were good and moist but not sopping wet. I cleaned the contacts with a scotchbrite pad and let the meter sit in the grounds for a couple minutes and the reading is 5.6. If you can try that:)

I'll try your coffee grounds experiment in the morning.(We use Maxwell House original roast. I've read that coffee ph can vary). I'll also get a better picture of the foliage.

By the way, in an effort to find another way of calibrating, and not knowing a Kelway doesn't do liquids, it I tried vinegar. My jug of white distilled vinegar says that it is reduced with water to 5% acidity. I looked on the internet and found the calculated ph for 5% acidic vinegar was 2.39. I cleaned the Kelway and stuck it in a glass of vinegar. It immediately pegged out. After a minute it began to slowly climb. It stopped at 4. Proves nothing if the Kelway isn't designed for liquids.

Thanks for the advice on the lime. I do mist every morning with well water so I'll up my time from 10 to 20 min and start checking ph more often.

Papa Jim

Bamboo Rabbit: I duplicated your coffee grounds test this morning and my Kelway posted a 6.2 compared with your 5.6. Close enough? Could be you like stronger coffee or a difference in brands?

Here is a close up of the browning foliage. It is only on the older leaves and covers only about 5% of the worse plant. I do notice that my leaves are small which if I recall from prior posts indicate that the plants could use some nitrogen. What's the best way to do that without making the acid situation worse?

Apapjim,

Yep I say that is close enough. My grounds are from an espresso machine and that or a different brand could be the difference. Ok so now we know the meter is accurate.

The red speckles on the leaves are a sign it wants more nitrogen so nothing to worry about there. The leaf damage to me looks like fungus, (probably gloeosporium.) again nothing to worry about. Do you prune right after your harvest ends? If not you should as it lets the bush push new leaves and growth in the summer that is just fresher and makes the plants get bigger faster.

Signs of too low PH are the same as too high. The leaves will sometimes get black spots but they will always be chlorotic, veins will remain green but the rest of the leaf will yellow. It is for the same reason as too high of a PH, blueberries are only able to take in iron at a very narrow PH range so too high or low PH shows same chlorotic symptoms. Sometimes people see the chlorotic leaves and assume the sulfur they added did not work so add more when in reality the plant was telling them the PH was too low and then they are dead.

At your PH they should be showing chlorosis but are not......have thought on this a bit and one reason could be that you did not apply the sulfur uniformly across the surface so some spots in the soil may have a ph in the correct range and the roots there are able to take up iron and keep the plants looking good. Easy to check just make multiple PH readings in the same pot.

Advice remains the same I would not add a thing to the pots except raw well water......the bicarbonates in the water will balance out the extra acidity. This is why I stopped using sulfur and switched to acidified water. Less guess work.

Bamboo Rabbit: I guess it will just remain a mystery why the plants are not showing distress. I did 4 reading per pot and have rechecked since then. If they look that good now, I can't wait to see them when I get the ph right.

Any ideas on what I can do with that bag of ammonium sulphate?

Thanks for all the help.

Papa Jim

Jim,

Like I said.somewhere in that pot where the roots are the PH is fine.....perhaps just the surface is too acidic and half way down in the pot the PH is fine.

You do have to get that PH up though and the well water will do the trick. You should see a difference in a week or two watering heavily every couple of days. It is the bicarbonates in the water that make the sulfur necessary in the first place......the PH or more accurately it's movement is because of the bicarbonates. Everyones water is different...my water is very high in bicarbonates so in a natural state it is horrible for the BB. Floral City Lou is 6 miles from me as the crow flies and his water is awesome for the BB and needs no treatment at all. His PH and mine are identical......the difference is my water is bicarbonate rich and his has very little bicarbonate. Rain water is best for the BB because it is almost bicarbonate free. But in your case you want the bicarbonate well water to negate some of the sulfur. How long that takes depends on how much of a bicarbonate load your water carries.

In the future just use a tablespoon or two of sulfur twice a year per BIG pot and you should not have any problems. Or just use rain water and use no sulfur at all.

Keep the ammonium sulfate and use it.....the stuff is AWESOME on all plants. Just wait till you get your PH issue sorted out to use it on the BB.

Wills - "switched to acidified water" - Will you expand on that comment? Are you using water in a large barrel and adding an acidifying agent?

Christine,

I have almost 200 blueberry bushes and while far from commercial I do the same as most of the Florida commercial BB folks and that is add sulfuric acid to my irrigation water. Sulfuric acid is simply battery acid......you can get the acid at any auto parts store. For batteries it is 33% acid. I bought a 55 gallon barrel of 96% sulfuric acid which will last me 15 years? A long time:)

What the acid does is reacts with the bicarbonates in the water and turns them to gypsum.......it is what the drywall/sheetrock in all our homes is made from. In that form it is stable in the soil. Once the acid has reacted with the bicarbonates the PH then starts to fall and when it hits PH 5 it is ready to use. You only have to measure out the amount of acid once and after that just add the same amount.

I have a 300 gallon mix tank....a tote. I picked up a whole trailer load of them I took one the rest went to Lou. Mounted to the tote is a 1 HP pump. So I start the filling and add 2/3 cup of acid and 4 cups of ammonium sulfate (so they are fed). I have that tank plumbed not only to my 3 blueberry beds but to every irrigation run on this property so I can give any line any soluble fertilizer mix I want to. For me it is just so convenient.

If anyone wants to try it just remember acid can be dangerous but it isn't like in the cartoons:) The 33% battery acid you can pour a bit in your DRY palm and it will start to sting after a bit but that is it......so what I mean is if you get it on you wipe it off and rinse and you are good. IF IT GETS IN YOUR EYES you are in trouble. Always add acid to water not the other way around. It deserves respect just like pesticides or gasoline. Acid is easy to use by the bucket as well..once you know it takes say 10 drops of acid to 5 gallons of water it will always take that much. Buy a $10 roll of PH test paper and experiment till you figure out the amount. Everyone's amount will be different due to your own water chemistry.

The acid allows me to get away with things you are not supposed to do with BB like use manure. The doc around the corner has 4 horses so I get the bedding and manure from them. The PH of the stuff is sky high but all that urine soaked pine makes such a nice mulch. Because I use the acid I just up the dose and use a cup per 300 gallons instead of 2/3 for the first couple of weeks and the acid balances out the high PH urine.

Sulfuric acid is NOT organic. While it does occur in nature on some planets on ours it does not. Sulfuric acid is regarded as GRAS (generally regarded as safe) by the government. The university of Florida recommends the sulfuric acid for water treatment on blueberries.

If you feed them right and get the PH right the plants respond well.

{{gwi:72471}} ...

Back in August the ph in my potted blueberries was 2.8. You suggested lots of water. They have been misted 20 min every morning since then. The average ph is now 4.3. Thanks again!

Papa Jim

Glad it worked out:) Plants showing lots of fruit buds for the coming season?

BR, I've got some buds but not a lot. Just not enough cold weather? I think the temp has only gone down to 45 one night so far.

Papa Jim - I'm sure that your bushes will be full of buds very soon. I checked mine yesterday and I saw that my 30 BBs are loaded with buds.

Jim,

You should be able to see the buds now. Long skinny buds will be leaves the round ones will be clusters of berries.

Question for Bamboo_rabbit or anyone else who has experience with using acidified water for growing blueberries: how do I transition from sulphur to sulphuric acid without getting the pH too low? My blues were planted with plenty of sulphur near the rootball, but the beds I put them in have only been top-dressed. I've put in enough sulphur to get the pH down to about the 4.8-5.2, range, but I know it's going to take awhile given the high clay and OM soil conditions and given that it was mostly top-dressed. My question is, will a sulphuric acid solution of about 5.2-5.5, in conjunction with the sulphur, cause areas of my beds to become too acidic? My understanding with sulphuric acid solution is that it is not buffered, so had little long-term effect on soil pH, that the low-pH condition is created by frequent watering with the solution, etc. but I wanted to be sure by asking an experienced blueberry gardener who has experience with both methods of acidification.

My starting pH is right at 7.0, the soils in my area tend to be slightly acidic. I made the newby mistake of using mushroom compost when I started the bed, which I then neutralized with aluminum sulphate (before finding out that aluminum sulphate can cause toxicity issues). I've had the sulphur in the soil for just over one month with a current pH of about 6.7.

Erik,

As I am sure you know but for others that don't....powder or pelleted sulfur is a pain in the butt. When you apply it the stuff takes forever to work as it has to be acted on by soil bacteria to "release" the acid. The process can take many months to fully resolve, up to 18 months I have heard. So people add sulfur the PH is still too high so add more, and more then it really starts to work and the PH plummets. Bad news and game over for the plants.

I transitioned from sulfur to sulfuric acid as well. You will need a meter I would suggest a Kelway, about $60. It is a direct push in the soil read the dial meter. When I started to acidify I would notice huge swings in the PH from the peletted sulfur.....some spots were PH 3 others were PH 6, just depended how evenly the sulfur was scattered. Now 2 years after I switched over the entire bed is exactly the same PH that I can adjust at will. If the PH creeps up I add a bit more acid till it comes down...if the PH is too low I can just irrigate with the high bicarbonate water and the PH rises. No more guessing. I have overhead sprinklers in all 3 of my BB beds for freeze protection. That water is straight well water so high PH so my PH in the spring tends to be a bit higher than I like but is so easy to adjust.

To answer your question..yes it is possible your PH will get too low but I think it is unlikely. Because you are in control of the water PH and bicarbonates instead of using PH 5.2-5.5 adjust down to PH 6 or 6.5 water. That way you are still adding some bicarbonates to the soil and that will buffer the sulfur you have added. In a few months as the sulfur is used up you can lower the PH of the applied irrigation water. That is what I would do.

OR

You can still use the 5.2-.5.5 water but monitor the PH and if it starts to get too low use non acidified water as the bicarbonates will do the buffering for you and bring the PH back up. .

All in all I think the first choice is the best choice. It took my beds about 6 months to stabilize.

Where are you located btw?

BR,
I just tested my fresh batch of Chock-Full-of-Nuts-coffee grounds and my Kelway reads 6.6 PH. So I'm assuming there is a big difference in the many brands of coffee people use. I don't like strong coffee as I drink coffee all day long.

Lou

Thanks Bamboo! I'm located in northern Arkansas; I'm growing northern highbush with a preferred pH range of between 4.8-5.2, a bit lower than rabbiteye or southern highbush. I'm just north of the northern/southern cutoff for blueberry varieties. I've read a number of your posts regarding the use of sulphuric acid and I've learned a lot from you so far - I read several sources from the U of F and NCSU that you recommended. Much appreciated!

I have a Burpee pH gauge currently. I'll get a Kelway - I assume it's more accurate or easier to use?

Bamboo, I ordered my Kelway as you recommended today - I read some reviews on the Burpee and found out that's it's a piece of junk. Good thing my blues are still dormant... I read your advice to dilute the sulphuric acid, measure how much is needed to reduce the pH to about 5.2 for the size watering vessel being used and then just keeping using that same quantity in the future. You mentioned that Kelways cannot test the pH of water - what method do you recommend to test the pH when determining how much acid solution to add?

Thanks again!

Ah, I re-read your earlier posts. $10 roll of pH paper. Thanks!

Lou,

Try cleaning the contacts on the Kelway with a scotchbrite pad, or did you? If when you push the probe in the needle does not bounce to the right before falling back to the left the contacts are dirty.

Erik,

Always glad to help:) Keep us updated on how the plants are doing. The BB here are just starting to ripen.

BR,
I did use Scotchbrite to clean the contacts then stuck it in the damp grounds from the coffee I just made. The needle moved to the left only and it went down quickly to 6.0 then slowly crawled back up to 6.6 and stayed there solid. So I'm assuming my brand of coffee is rather mild in acid. Tomorrow morning I will test it again when I change the filter and I will use Folgers coffee to see if there is any difference in the PH.

Lou

BR,

By following your advice here and on other threads, I've gotten my pH holding at a pretty consistent 5.5. Your advice to get a Kelway is spot-on - it's hand's down the easiest/quickest pH gauge I've ever seen and it's not delicate like most others. I'm going to get the pH down to about 5.0 by continuing to use acidified water; since I have sulphur in the soil, I'm going to take my time with it so that the pH doesn't get too low when the remaining sulphur kicks in. We're a few climate zones cooler where I am, so my blues are just now breaking dormancy - I'll post some pics as they grow & develop. When I first started, my main fear was that I couldn't get the soil acidic enough, fast enough, but sulphuric acid solution at about a 5.0 pH sure does the trick fast, without all the frustration (timelag) of sulphur and the complications of sulphate.

The system I developed that works well for me so far, has been to purchase a new 5 gallon diesel can (in a contrasting color to my gasoline can, so that I don't confuse the two). I filled it with just over four gallons of rain water and then added two new battery refill kils (about 1 liter each), and then topped it off with rain water. Using my narrow range pH paper, I determined that about 1/4 cup + 1 tablespoon gets me to the 5.0 range; I plan to use a second table spoon when I'm trying to decrease the pH and one less when I'm trying to bump it up a bit. My near-worthless Burpee soil tester has found a second life double-checking my pH paper for water (I think the problem with this thing is that it's much better for testing liquids than it is solids - it doesn't work the way the picture on the box shows as a direct tester, even when the soil is very wet).

I picked up one of Monrovia's "Bountiful" blueberries today, thinking it would fit well in the the landscape in a foundational setting (my more conventional northerns are in a hedge planting in the front yard, three facing south, five facing west with 12 hrs+ sunlight). So far, I'm having trouble finding out a lot of details about this variety, I'm assuming since it's proprietary with only one source - does anyone have experience with these? Coming from the nursury where they've been in a greenhouse, they're already done blooming and are well-along to harvest - which my Northerns (Duke, Blueray, Bluecrop, Earliblue and Ozark, a Northern/Southern hybrid) are just now budding out heavily. Which makes it difficult to know what's a good pollination partner for the Bountiful.

Erik,

I'm glad you found my blathering helpful:) It is always good to hear back from people both positive and negative. Using Pelleted sulfur is like dancing with a brontosaurs lol. The acid on the other hand is so exact, so grateful and easy to use.

The system you developed is great.it allows you to work with the acid in a more diluted state which is safer and easier to measure accurately.

Not sure on the BB you bought but you are right you may have to wait till next year to see when it's natural bloom time is. Here our berries are just ripening. I have not picked yet as I like to let the berries hang blue for a few days but have been grazing:)

Bamboo,

When do new canes typically emerge? Do you summer prune? I happen to live near Berries Unlimited, a major supplier to commercial growers - the owner there advised me to summer prune after harvest to force new growth (I recently bought two new Elliot's and Spartan). The source seems sound but it runs contrary to the usual advice on pruning, so I wanted your opinion too.

Your advice on watering with sulphuric acid and to use a Kelway was spot-on; I love my Kelway, it's easy-to-use, very quick and accurate. I keep a brillo pad as you recommended; also great advice, I've been watering with a pH of about 5 and I've been maintaining a pH in the bed of close to 5 (I water with 5 gallon buckets and concentrate watering closer to the my plantings, so the low pH is concentrated near the plant centers).

I've expanded my hedgerow to include 11 northern blueberries - two Reka, two Elliott, two Bluecrop, one Blueray, one Ozark, one Spartan, one Duke, one Earliblue. All of them are thriving, in no small part due to your advice.

A nice discovery I've made recently that I haven't seen recommended before in most of the literature on growing blueberries - use folar feeds of chelated iron once a week or so after budbreak until the first flush of leaves is grown. Doing so keeps the iron levels high, even if there's some flucuation on pH levels. I sprayed mine as a preventative and it seems to be working great. Chelated iron should help with either pH being too high or two low and buys you time to correct the pH before iron chlorosis sets in.

Pictures? ;-)

Much good info in this thread. I'd just like to point out, the correct term is pH, not PH, not Ph and not ph. I know-sticklers for proper spelling etc. are mostly disliked here in forum land. But, if you want to look like you know what you're talking about-or writing about, as the case may be-that's how the term is written.

I have the same set of conditions way up here in Wisconsin-a high pH water source derived from limestone bedrock in the area. For me, soil sulphur is not a pain to use at all. In fact, it is my material of choice for this problem. And while I'm not growing blueberries, I get into much the same area with some of the ornamental things I grow, such as petunias. The other thing that is both easy and efficacious is to use "acid special"-type fertilizers when you water. So, here I'm obviously talking about water-soluble materials. The N source is urea and/or ammonium in these fertilizer types, and each time you water, you're doing a moderate adjustment of the soil pH. This became a must for us after the release of such now-commonplace items as surfinia petunias and the like, with their even higher demands for acidic growing medium.

Of course, there are no free rides in this world. If one uses too much of these acid-special types of fertilizers, significant internodal stretch can be seen on your plants. The ammonium/urea really causes a lot of stretching. Two things can help here: First, watch your phosphate levels. Phosphates do the exact same thing-cause internodal stretch. So reducing the phosphate levels can really help to keep your plants nice and compact, not to mention, phosphates escaping into our waterways is a huge source of algae blooms.

+oM