Has anybody experimented with a homebrew starting/potting mix?

JosephineRose · April 9, 2019

Once I started paying attention to price, I started making my own seed start and potting up mix. Haven't graduated to my own container mix yet but it is coming. I have played with a coir/peat combo for giant grow bags on onions only. I need to get my compost bin at the new house really singing and then I will try my own mix.

Generally I have found the coir very drying to my plants and also causes them to yellow. I have yet to have a good experience with it as a primary medium.

I buy the sunshine organic peat moss by the bale at home depot and one bag giant of Vigoro perlite and one of vermiculite. I always have a bag of worm castings around. I buy these once every two years or so and it lasts me forever. Costs less than $60 out the door... the seed starting mixes alone are $8-9 for a small bag.

My seed mix is 5 parts finely sifted peat, two parts vermiculite and one part perlite. I find the worm castings in starting mix promotes fungus so I avoid it until the plants are ready to pot up and are seeking more nutrients.

The potting mix is also 5 parts sifted peat (though I use a wider sifting insert on it), two parts perlite, one part vermiculite and 1-2 parts sifted worm castings.

April 9, 2019	#17
JosephineRose Tomatovillian™ Join Date: Feb 2016 Location: California Posts: 383	Once I started paying attention to price, I started making my own seed start and potting up mix. Haven't graduated to my own container mix yet but it is coming. I have played with a coir/peat combo for giant grow bags on onions only. I need to get my compost bin at the new house really singing and then I will try my own mix. Generally I have found the coir very drying to my plants and also causes them to yellow. I have yet to have a good experience with it as a primary medium. I buy the sunshine organic peat moss by the bale at home depot and one bag giant of Vigoro perlite and one of vermiculite. I always have a bag of worm castings around. I buy these once every two years or so and it lasts me forever. Costs less than $60 out the door... the seed starting mixes alone are $8-9 for a small bag. My seed mix is 5 parts finely sifted peat, two parts vermiculite and one part perlite. I find the worm castings in starting mix promotes fungus so I avoid it until the plants are ready to pot up and are seeking more nutrients. The potting mix is also 5 parts sifted peat (though I use a wider sifting insert on it), two parts perlite, one part vermiculite and 1-2 parts sifted worm castings. Last edited by JosephineRose; April 9, 2019 at 02:59 PM. Reason: Peet's is a coffee, peat is a moss.