Blueberry pH maintenance

I’ve been growing blueberries in pots, this is my third season with them. My mix initially was 50% peat and 50% pine bark. The blueberries have been doing great! I try to water with rain water as much as possible and I use Espoma’s 4-3-4 acid fertilizer which contains 5% sulfur. Is this enough or should I add additional elemental sulfur to keep the pH down?

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The only way to answer your question is by measuring the pH of your media. Even then it’s not easy because the lag time of sulfur is so long. My experience says that if the plants are doing great, don’t change a thing. I’ve killed them with too much sulfur. And when the pH gets too low it’s a pretty deep hole to climb out of.


My experience too. Quite a few strategies out there to get the Ph down.

If you are like me, you implement several of them and turn your soil into something resembling battery acid.


Not the first instance of “killing it with kindness” I’ve heard :wink:


Blueberry newbie here.

  1. Does anyone have any specific strategy to maintain ideal pH for blueberries in ground or in mounds?
  2. How many times per year do you guys test pH? Or is being reactive a sufficient enough strategy once you observe visually something is amiss with the plant.

In my experience with municipal water, you can amend your bed all you want but if the pH of the irrigation water is greater than that of the soil, then the soil pH will rise.

Another thing to keep in mind is that different blueberry cultivars can have different pH preferences.


What is everyones favorite way of measuring their soil pH?

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I wouldn’t worry so much about ph. As long as you are in the ball park you will be fine. My soil ph is above 7 and the bushes seem to be doing alright. I did amend the hole and mulch heavily. But after 5 years these bushes extend their roots well into native soil.

Phots taken today.


Hanna soil pH test apparatus.

What cultivars do you have?

Duke, chandler, Elliot, spartan, liberty, Berkeley, pink lemonade (this one does really well). A few others too. The more I water (drip line) the happier they seem to be.

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I got some strips off the web for like $9. Geared for human saliva and urine, but they work.

I used to go do the thing where I get a representative soil sample, put it in a coffee filter, poured distilled water through it and tested.

Lately, based on a post I saw here, I just poke a hole in the ground, pour distilled water around it, slowly pull the strip out after about a minute and test.

Works well enough 90% of the time.

I do notice that the successful growers (not me) are somewhat laissez-faire about the PH thing.

If I try again I will strive to get my soil under six before planting. After that I’ll play it by ear and depend on incremental post-planting adjustments to get where I need to be.

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Both of those methods are grossly inaccurate, but they will tell you if your soil is acidic or alkaline.

How much new growth (inches) do you usually get annually?

Against an actual university soil test or two I was only off by 0.1 Ph.on the coffee filter method. I doubt the test strip in the hole with the distilled water around it method was much different.

Depends on the quality of your test strips I imagine.


I’ve never measured, so hard to say. My blueberries don’t get full sun, more like .6 or .7 so that is a large variable as well. They are def less vigorous than the blueberries in more ideal locations like western Oregon.

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I just piled on more in ground garden soil from Costco, I top them up. It seems to work so far. I don’t know what varieties I have but when I bought them from the farmers market, I selected the ones with big blueberries already. The plants I ordered from Raintree nursery never produced anything good for me.

While PH is a concern, the most often missed problem with growing blueberries is their preference for highly organic soils. It is generally a good idea to add things like peat moss and pine bark fines to the soil around blueberries yearly. Caution that these absorb nitrogen and may require a supplement to maintain normal growth.

What is normal growth? That depends on the crop load, variety, species, soil, and climate. I have rabbiteye blueberries that grow up to 2 feet per year. A couple of my southern highbush usually grow about 8 inches yearly.


Strongly disagree.

Within the context of a backyard garden, the pH strip method is going to be more accurate than using professional equipment such as digital meters.

Before you try to point out that digital meters are x-number of orders of magnitude more accurate, recall that all pH meters need to be calibrated on a regular basis, and not only does the typical backyard gardener not likely know the process to do so correctly, they are also unlikely to have the correct reagents. Even assuming a backyard gardener goes through the considerable expense of getting a good meter and the reagents for calibrating it, realize that those reagents have a limited shelf life, especially given the kind of storage conditions they are likely to be in.

No, in the context of backyard gardening, pH strips are far more reliable than “objectively” more accurate pH meters. Of course, it’s also a good idea to have soil tests done through the ag extension office, but, if I may draw a comparison, it’s a bit overkill to have a full blood panel done just to check your glucose. On an annual basis? Sure, it’s a good idea, but for doing a quick pH check for some blueberries or azaleas? Not the appropriate tool.

And, while this is just a quibble, the notion that pH strips are only accurate enough to give a binary result is unfounded, I suspect you’re passing off conjecture as fact here. If we look at actual data collected so far: the other commentor found his tests were actually within 0.1 of the lab results.

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This is a really good point. Thank you!

I have a related question: is it appreciably better to plant blueberries in the spring or fall? I’ve heard people say the one or the other, but little in the way of why.

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Thanks @Phill_Boise_7a . That answers a question for me as we have very chalky soil but about to move my pots into the ground with plenty of surrounding ericaceous soil. I was worried about the roots spreading beyond the acid soil.

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