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squirejohn

peat moss/lime ratio?

Is there a "rule of thumb" that would raise the pH of peat moss to somewhere between 6.0 and 7.0? For example for every 5 gal. pail of dry peat moss add x amount of powdered lime to raise pH from ...

Comments (9)

  • jolj
    12 years ago

    Not that I am aware of, what do you want to do.
    There maybe another way to skin this cat.
    If you need Organic Matter, but want a high pH 6.-7. then try shredded leave in a compost pile.As the leaves rot the pH goes up.
    Have you Google pine bark, or other ground up Organic Matter?

  • TheMasterGardener1
    12 years ago

    I have just planted some lemon bamb in 1 gal pots. The mix is about 3 part peat 1 part perlite. So with the peat being about 4.5 ph it is way to low for the plants. I was in a rush when I planted them and I did not add lime. I was going to add about a tbl spn of lime per gal of mix. I believ that should bring the ph to 6-7. I will top dress with 1tbl spn per plnt to get the ph up.

    So in your case it could be 5-6 tbl spn of lime per 5 gal of peat. Please somone correct me if im wrong.

  • TheMasterGardener1
    12 years ago

    Yea. The peatmoss becomes 7 after time. But if you look up the ph of fresh moss it will be 4.5 or lower.

    I just adding my lime to my 1 gal pots and i think I over did it and went with about 2-3 tabls spoons of lime each pot. opps! I hope that the lemon bamb will like it I hear it likes ph up to 8.5 so I think I changed the peat4.5 to about 7.5.

    I hope somone has some more views on this. I do not have a ph tester.

  • Kimmsr
    12 years ago

    Peat moss, organic matter, has a pH of around 4.5 or so. Oak leaves, organic matter, has a pH of around 3.2 and pine needles, organic matter, has a pH around 3.7. Since Abigail Maynard did research at the New Haven Agriculture Research Station that found that Oak leaves and Pine needles will have no significant affect on soil pH, why would anyone think peat moss would?

  • squirejohn zone4 VT
    Original Author
    12 years ago

    Well I mixed up some peatmoss and powdered limestone using a mix of 1,4,8 and 16 tblspns per gal. of peat. I added the lime to dried peatmoss, mixed up thoroughly, wetted the mix by strirring in water, dried the mix by squeezing in a paper towel, and took the pH. I used a Corrnell Univ. pH colorimeter kit (5.2 - 7.0) and didn't see any change in pH until 16 tblspn. (1 cup) mix which resulted in a pH of about 6.0.
    After reading the above posts I don't think I need to be that concerned about pH. I plan to use peatmoss for its water retention qualities as part of a mixture which includes topsioil, compost (don't have enough), and rotted cow manure. I have six trash bags of shredded leaves that I could also add to the mix but never thought about using them until reading jolj's post.

  • gardengal48 (PNW Z8/9)
    12 years ago

    Oak leaves and Pine needles will have no significant affect on soil pH, why would anyone think peat moss would?

    Because the fresh leaves and pine needles breakdown and decompose and their acidity declines with decompostion. Peat moss is already nearly fully decomposed organic matter and any further decomposition is a long and slow process, therefore it holds its acidity much longer. Hence its recommendation as a soil acidifier -- the effect is typically quite longlasting, kimmsr's unsual and anecdotal results to the contrary.

  • TheMasterGardener1
    12 years ago

    Thank you gardengal48 for clearing that up.

  • squirejohn zone4 VT
    Original Author
    12 years ago

    Thanks for the information gardengal48. I guess I'll be adding lime to peatmoss afterall.