Making my own Pro Mix Based soil

[Grass_Lover]

I just got a 32 cubic foot bag of pro mix and an 8 qt bag of perlite.

Initally I mixed some pro mix in with a little more perlite, I'd say about 3.5 cups to an entire rubbermaid tote filled with pro mix. My goal was to change the visual appearance of the perlite in my tote compard to the regular pro mix. (Pro mix comes with perlite in it,... I wanted to make my soil mix have a little more in it - I achieved this).

That's it. That was my soil mix. I used it to repot two 1footers and two 2" tall seedlings. I was afraid that my seedlings would get nute burn (Like they did with the miracle grow that they were previously in) if I added worm castings, or other natural supplements. Is this so? What if I were to plant seedlings into a strong soil such as foxfarm? Would the seedlings suffer from nute burn?

I guess those few questions above are all. I started writing this, had a few beers, returned... and forgot what else I was gonna add.

 

[GratefulPhish]

yes ive used that soil mix for seedlings with and without added castings with no burn. Should work out fine either way with the pro-mix. i mix mine 75% pro-mix 15% perlite 10% castings with a tbs of dolemitic lime per 5 gal.

 

[BurnOne]

Use ProMix, perlite, worm castings and dolomite lime to make a mix that can be used from everything from sprouting seeds to starting clones and from veg through flower to harvest...

LC's Soiless Mix #2:
6 parts Pro Mix BX or HP
2 parts perlite
2 parts earthworm castings
Powdered dolomite lime @ 2 tablespoons per gallon or 1 cup per cubic foot of the soiless mix.
If you use a 3 qt. saucepan as “parts” in the amounts given above, it equals about 1 cu. ft. of soiless mix and you can just dump in a cup of powdered dolomite lime.

Burn1

 

[sproutco]

Not adding anything to the soil other than dolomite lime gives you more control of what is being fed. You can add whatever is needed through the water as far as ferts. You also would have the ability to flush if too strong.

 

[GratefulPhish]

i agree sproutco, i believe the castings add good microbes tho

 

[Suby]

A healthy organic soil is based on soil elements being added to the original soil, with organics we are less interested in tailor feeding the plants but rather making whatever they need available in the soil at a resonable level and then supply more later.

I use Promix HP like this

60% Pmix HP
30% perlite
10% EWC

to which you add

2 TBS of dolomite lime per gallon of soil mix

this mix is excellent for seedlings because ProMix contains not nutes unlike MG or FF soils, the FF is really good for established clones or seedling though.

It's always good to have a neutral peat based soil like ProMix availble for seedlings and clones, I do a special starter mix of half PM and half perlite and that's it for the first week until transplant.

You can add lots of things to the base mic above to enrich your soil.
Sub's

 

[sproutco]

Promix comes with lime already added. Perlite has a high ph already. The small amount of earthworm castings are acidic so they require a little lime. Why are you adding 2 tablespoons dolomite per gallon of soil(which is alot)? Don't you end up with a high ph?

 

[Suby]

Hey man,

Perlite is substrate and when well rinsed before used should not affect soil ph.
Promix contains very little lime so I like to add it to my soil mix, I skip it for clones and seedlings and use 1/2 ProMix and 1/2 perlite.
Remember that dolomite lime is a buffer, this means that it creates a target ph, if you soil ph is acidic it will rise it towards high 6's and even 7, if your soil ph is rather neutral say almost 7 it will not overshoot 7, it will maintain the balance.
I have grower friends that use 2TBS of dolomite lime in coco which is ph neutral as it gets for a substrate and to no ill effect on ph.
Pot plants require alot calcium and magnesium, typicaly more than most fertilizers provide and dlime is chock full of both onced broken down by soil elements.