Acidifying soil for blueberries

Discussion in 'Fruit and Vegetable Gardening' started by Bonaventure, Jun 20, 2020.

  1. Bonaventure

    Bonaventure New Member

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    I have planted three pots of blueberries in 22" pots about 3 feet apart in my backyard for about a month. I have purchased those commercial pH meter (ones you can get from Canadian Tire or Home Depot) and the pH level seems to be slowly dropping from about 6.5 from the beginning to 7 now. I initially used tap water, but not that much since it has been raining a lot in Vancouver this month. Furthermore, I have just got myself a rain barrel so it can enjoy a bit more acidic rainwater soon.

    Nonetheless, the pH level of the soil still concerns me. While those cheap pH meter may not be very accurate, still 2 of the 3 blueberry bushes didn't seem to grow. The leaves are not yellow yet, but it does seem to pale a bit. The soil in the pots are regular potting mix and peat moss, mixed in 1:1 ratio. While some sources says peat moss should be acidic enough, it didn't seem to be the case for me (at least that's what the meter says). I read that applying ammonium sulphate does the trick in the short term, while spraying elemental sulfur works nicely in the long term. However, I am having difficulty finding these either online or at local large garden stores. In fact, the stores often suggest the use of aluminum sulfate, which I do use for Hydrangeas, but I read from many places that it is toxic to blueberries (despite the package says it is great for BB?!)

    So any advice to acidify my soil for the BB? And where can I get them?
     
  2. vitog

    vitog Rising Contributor 10 Years

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    I used elemental sulfur pellets for acidifying the soil that my blueberry bushes are growing in, and it worked quite well. I bought the sulfur at the Otter Coop in Aldergrove; but it came in a 20 or 25 kg bag, which is way more than you need. Try phoning them to find out if there are smaller lots available. You mention the type of soil in the pots, but what type of soil are the bushes planted in? I assume that the pots have been removed, and you will have to acidify all of the soil around the bushes. I have well-draining, sandy and rocky soil that is not ideal for blueberries; but since I applied sulfur and a mulch of wood chips, they are doing quite well.
     
  3. Bonaventure

    Bonaventure New Member

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    I mixed regular potting soil with peat moss in a 1:1 ratio in that 20" container where I migrated the bushes. I plunked a few holes at the bottom for drainage so that part should be fine.

    Thanks for the tip I'll call them to find out.
     
  4. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    Hi, can I just add that the most important thing for my Blueberry bushes was watering only with rain water. I see you have purchased a rain water barrel, so this will help. Tap water in my area is so alkaline and full of chemicals it kills them very quickly. I carry out rain water harvesting for all my trees and plants, they love it.
    I also mulch with a little peat each season, to help with acidity.
    Btw the Autumn colour is quite spectacular, so apart from the delicious berries, you have the added fiery reds to look forward to.
     
  5. Bonaventure

    Bonaventure New Member

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  6. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    Good morning @Bonaventure, yes this will help increase tbe acidity, but IMO what you are using with your compost mix already should be fine 'in pots'. If planted in the ground with neutral to alkaline soil then sprinkling this would be beneficial.
    If you do use the garden sulphur then use sparingly.
    Also I would not rely totally on the readings of your meter.
     
  7. Bonaventure

    Bonaventure New Member

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    My meter kept saying the soil was pH 7. It does read about 6 when I watered them to acidic mix (Miracle gro water soluable for acid living plants). But a few hours later the meter reads 7 again.
     
  8. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    7 is neutral, you did day you were getting a water barrel, are you using tap water atm? If you are in a hard water area then that will increase alkalinity. Your meter is also possibly wrong. How are the bushes looking atm ? If they have healthy leaves all is fine. If they do not like the alkalinity of the soil they will soon tell you.
     
  9. Bonaventure

    Bonaventure New Member

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    I have been using rain water for over a week now. Had some good rain this week in Vancouver. I am not so sure about the accuracy of the meter, though I did test it by soaking into the acidic solution that I used to water the BB (the one mentioned above) and it did read slightly below 6, which is similar to the reading on soaked soil just when I water them with the solution.
     
  10. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    Hi if they look fine then just monitor over the next couple of weeks. Blueberries are hardy if the soil is right for them and as I said earlier they will soon let you know if they are not happy. You are doing everything right btw.
    If you get leaf colour change then add a little sulphur you purchased, but not yet. Do let the forum know how you are doing with updates and photos if possible.
     
  11. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    Hi @Bonaventure, I have added this link to the posting, as it is what I have worked by with my Blueberries. How to grow blueberries / RHS Gardening

    Hope this is of help

    D
     
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  12. Bonaventure

    Bonaventure New Member

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    The one on the blue pot is the biggest one and it has visibly grown a bit since I planted it. The ones in the yellow and red pots are the smaller one and they didn't seem to throw. Also, the one in red seems to have its leaves turning a bit red. I am not sure if this is a problem or if it is the type of BB (Duke).

    I just spray a handful amount of garden sulphur near their roots by removing the munch and top soil and reapply them afterwards.
     

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  13. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    Good morning Bonaventure, tbh IMO they all look very healthy. Keep doing what you are doing and you will have very happy fruiting Blueberries. But remember as the season progresses the leaves will turn red before dropping in the Autumn. Some sooner than others.
     

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