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galiana_gw

Red Blueberry Leaves, pH Test Inconclusive

galiana
10 years ago

Hey folks,

We planted 6 blueberries the other day (2 Northland, 2 Bluegold, and 2 Duke). The leaves on each of the bushes have started turning ruddy, which I know might indicate a pH imbalance -- but I'm having a difficult time in getting a pH test to turn out conclusively.

These are in the ground. We bought in soil (1/2 topsoil, 1/2 compost mix) and mixed that approximately half and half with peat moss. My husband added sulfur -- I think he went horrendously overboard and added 10 lbs for our 90 sf bed.

I tested the soil mix before adding sulfur, but despite drying the mix and winnowing out (or trying to winnow out) all the big pieces of organics, the soil mix would never settle out enough for me to actually read the indicator liquid.

I have started another pH test (soil taken from around the bases of the worst-looking plants), but it likewise is not settling out.

Do you have any suggestions for me? The sulfur was only added at planting time and mixed into the entire top 6 inches of the beds -- but since we only planted a week ago I'm not sure how we could be too low on pH.

Thanks for any suggestions.

Comments (12)

  • Bradybb WA-Zone8
    10 years ago

    Hello galiana,
    Yes,that's a lot of Sulfur for that size space and it could take up to a year to reach it's full effects.I usually add about a half cup of Sulfur per plant.
    If it were mine,I'd probably remove most of the upper part of the mix and add more Peat and perhaps Pine or Fir bark mulch.
    Very low pH can be as detrimental as too high. Brady

  • fruitnut Z7 4500ft SW TX
    10 years ago

    I think your plants look pretty good. That color doesn't seem indicative of pH issues. A week after planting it couldn't be. Wait until fall or next spring to give the sulfur time to kick in before changing anything else.

  • Ernie
    10 years ago

    That's a lot of sulfur, especially if your amended soil is half peat, and it could very well cause problems down the line. On the upside, sulfur is very slow acting, so it shouldn't be causing problems for you at this stage. Are the blueberries in raised beds/mounds, or did you dig out holes in your native soil and fill with the top soil/compost/peat blend? How deep is the amended soil?

    As for the red leaves, that's nothing to worry about. The first flush of leaves will often have a reddish cast in the spring.

    ***

    Edit: I see that brady, fruitnut, and I were all replying at the same time. You should seriously consider brady's advice about removing a good portion of that top 6" with the sulfur and replacing it with pine bark, which has a pH that's usually ideal for blueberries. Alternatively, get an accurate pH on your amended soil ASAP. That way, you'll know for sure what that amount of sulfur is likely to do to your pH once it breaks down.

    This post was edited by shazaam on Wed, Jun 5, 13 at 11:56

  • galiana
    Original Author
    10 years ago

    Thanks all for your replies.

    I should probably have said that the blueberries are in raised beds rather than "in the ground." They're essentially very large stone and wood planter beds that run along our foundation. The attached picture shows a little better what the setup is. The beds are 4 feet wide, 27 feet long, and 2-3 feet deep depending on just which part you measure.

    We dug out all the soil that was in there down to the underlying rock -- about 2-3 feet. Then added our mix (as outlined above) and the berries. The current mulch is cocoa shells.

    The whole operation took 3 yards of bought-in soil mix and almost 4 35cf bales of compressed peat, along with all the sulfur my husband added. (The sulfur is only mixed in the top 6-8 inches, however.)

    I had hoped that the peat would give the berries enough acid while the sulfur took its time to kick in -- but these are my first berries, so I have no experience of what they ought to look like when they're first planted.

    I appreciate your insight.

  • fruitnut Z7 4500ft SW TX
    10 years ago

    Wow, that's a beautiful setup. I hope it works out for you.

  • Ernie
    10 years ago

    That's a very nice setup, galiana. I asked about the amended soil depth, etc., because I wondered if the pH and composition of your native soil would be a factor -- with a 2' to 3' bed depth, it probably won't (blueberries, as you might know, have relatively shallow root systems). So, to elaborate on the sulfur and pH issue, let's say that your top soil/compost is a bit alkaline at pH 7.5 (this is a purely hypothetical number) and that the peat has a pH of 4.5 (which should be reasonably accurate). Then let's say that your combined pH comes in at about 6, and let's call your soil mix loam (as opposed to clay or sand). In that scenario, you'd need approximately 3.5 lbs of sulfur to lower the pH to 4.5, and 10 lbs of sulfur could very well lower your pH below 4.

  • fruitnut Z7 4500ft SW TX
    10 years ago

    Shazaam:

    I like your calculations but those things are difficult to estimate. Personally I'd not tear up those beautiful beds. I'd suspect the plants will be OK. If not they can be replaced next year.

    We've discussed too low pH issues before. But I've not so far seen convincing evidence of real damage. If someone can even show me what too low pH looks like on a blueberry plant, I might change my mind.

  • drew51 SE MI Z5b/6a
    10 years ago

    Check with the water dept if you have city water what the PH of the water is. This could be used to counteract all the sulfur. I would not rip it up either. I agree with fruitnut even at 4.0 blueberries still should grow. And if your water is basic (and most ilkely it is very basic). Your going to end up adding more sulfur in the future anyway. I try to use rain water when I have it. I do have 100 gallons right now (yeah!).

  • Ernie
    10 years ago

    You're probably right, fruitnut. I tend to be a safe rather than sorry kind of person, so my advice is based entirely on what I'd do if I was in galiana's shoes. You could probably remove the top several inches of soil without adversely impacting the newly planted bushes, so it would just involve a little labor and cubic yard or two of pine bark fines. That being said, I definitely take your point about the difficulty of estimating these kinds of things, and my hypotheticals are purely hypothetical. If the pH did dip too low next year and if that had a negative impact on the bushes, then I suppose you could potentially flush some of the sulfur out of the soil with a large volume of water? I know from blueboy's experience that it works with potted plants, but it would definitely be a bit more complicated with a large bed. Still I can't argue with a wait and see approach...

  • northernmn
    10 years ago

    If you have high pH well or city water, you can raise a low pH quickly by flushing. The only thing that I would do now is to get comfortable with a good pH monitoring program. Adjust as needed.

    Try using a doubled or tripled coffee filter to eliminate the sediment on you pH tests.

    I have 2 or 3 varieties that have reddish leaves every spring. They are in the exact same soil mix as the varieties that don't get reddish leaves in the spring. I wouldn't be worried about that @ this time of year. Especially with spring coming so late.

  • ericwi
    10 years ago

    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.

  • Bradybb WA-Zone8
    10 years ago

    fruitnut,
    I have an Emerald in a container and it is about 3-4 years old.At the time I was potting it,I must have been in an add Sulfur mode.
    Months later,I'm checking out my plants and the Emerald's leaves look like they have Chlorosis.So I stuck a pH meter at different places in the soil and it was pegging the meter in the acid range at a number of spots.
    I don't think I took a picture of it,but the symptoms look just like high pH.
    After removing the plant and flushing off in tap water and repotting,it is now healthy looking,but it took over six months to come back. Brady