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peat moss pH...liming #177800

Asked April 28, 2014, 2:25 PM EDT

Hello. I want to make my own potting soil for seedlings. It will consist of mainly peat moss. Other ingredients:perlite, worm castings. Since peat moss is considered to be acidic, I will need to add lime to bring it into a 6.2-6.5 range. If I had a 5 gallon bucket filled with straight peat moss, how much lime would I nedd to add? Thanks.

Josephine County Oregon

Expert Response

If you want to make a good potting soil for seeding in I can share a couple of recipes from an ATTRA organic potting mix publication. Just keep the proportions the same no matter the volume you use.
75 percent sphagnum peat moss
25 percent vermiculite (can be perlite)
5lbs of ground limestone per cu yd of mix

Here is another close to what you want 
6 gallons of sphagnum peat moss
1/4 cup lime
4.5 gallons of perlite
4.5 gallons of worm compost
1/2 cup bonemeal
2 cups rock phosphate

In your example with 5 gallon bucket of peat moss
you would use 1/5 cup of lime
I would add about 1.5 gallon of vermicompost
and 1.5 gallons of perlite

Steve Renquist Replied April 29, 2014, 6:27 PM EDT

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