I found this chart a couple of years ago when Dad and I were arguing about the economy of compressed bales versus loose bags. It gives the number of different sized pots you get from a given sized bag (go down to the fourth page). Although it is for Fafard it works with Pro Mix BX products also (that's what we use). You will have to figure approxamatly how many trays/pots you are going to use and do the math from there. Hope this helps out.

Tom

Here is a link that might be useful: American Clay Works

Yeah that does help! They fill a lot! I think 3 will cover just under 1500 trays and 1 will do 400 4 inch pots.

So is the High Porosity better? Because last year I pulled a lot of chunks out of the BX.

Those compressed bales are about 7 cubic foot and it does A LOT. I'm going back to Miracle Grow after using the ProMix with BX with my. It was too peaty for my liking. I still have left from last year and will probably mix it with the Miracle Grow with Moisture Control for some of the pots. Or maybe mix it with the compost that I got locally made from leaves and horse poo.

When you moisten the bales, expect to need LOTS of water, it's really really dry. I had to add about 2x as much water to each part of bale. I used a 4'x4'x2 box plastic lined and it barely held the whole bale. Each bale weighs about 60 lbs dry.

Marla

I used one Pro Mix BX bale last year and one with biofungicide bag.

I have bought 10 bales last year, plus 2 cubic yard of compost, and I have 3 bales and about 1 cubic yard left. A good amount to get started this year.

I don't care how much you bought. I just didn't want to be treated like I have never bought seed mix before.

sorry, didn't mean to upset you. I don't buy the regular 'seed starting' stuff, haven't had any luck with that, has you? to be, it's too soft.

Did you like the bales? I'm not sure I like lifting the 60# too much. I planted about 3000 4" pots, close to 180 trays and about 30-40 gal pots out of what I used last year.

I placed my order yesterday. 2 bales of High Porosity Pro Mix BX and 4 bags organic potting soil.

Unless you really like spending money, you could just make your own potting soil. It's very easy to make, you can adjust it for different needs and cost very little.

I was also wondering why you don't make your own. I have been making my own for 19 years with good results every year.I used to use a peat/compost base but a few years ago switched over to coir instead of peat and like that a lot more as peat is so acid and so hydrophobic. Coir is neutral and sucks up water like there's no tomorrow.

I know that Lucy has posted her recipe in the past, could you repost your recipes?

Maybe i'll have to try switching from peat to coir. I've never noticed an issue with the peat other than there are some real twiggy brands I avoid.

This is my recipe for all my potting soil, seed starting only varies a little.
6-8 parts compost
2-3 parts peat
1 part sand

I screen everything down to about 1/2", finer for some plantings.

I make a special pile of compost every summer for the following years soil mix. Mostly it's animal manure mixed with some vegetable residue. Rabbit manure is the best but I also use chicken, cow, llama. Try to avoid really weedy (horse) or mucky manure.
Also make sure the manure source doesn't spray weeds with Clopyralid. I could go in to the gory details of my experience if anyone is interested.

-Mark

This post was edited by madroneb on Fri, Feb 8, 13 at 13:07

I use vermiculite that is sold as insulation and mix in a little compost as food. The bagged compost I've been buying is made of composted shrimp shells.

For the same reason my husband won't change his own oil etc etc. I don't want to make my own, been there, done that.

A bale of seed starting mix hardly costs more than a bale of peat along with additives. And then you gotta mix it up in the basement without the cats getting involved.

Minnie - your missing something there. All you have to do is buy the peat, put it out in the basement and the cats take care of all the additives you need. They will even stir it in for you.

Tom

composted shrimp shells? never heard of that but sounds interesting.
we mix our own out of locally purchased top soil, peat moss, perlite, vermiculite, screened compost (depends on crop, this maybe left out). We add a bit of lime, blood meal, and bone meal. not very much of those. we make soil blocks.

Tom, the smell of the cats helping is more than I want.

LOL. That would be fun to sleep with, dirty cats.

No, the cats are outside, but they really enjoy the hoop house, since it's nice and warm and dry. They just think any dirt is a litter box. Basic farm cats.

The cats are clean, but what they leave behind can really smell.

{{gwi:1037386}}
Then you have never seen paws this white! My cats try to get into the potted herbs so I mulch/rock them and then they are all around me when seed starting and I have to keep my eye on them. I keep them out with clear shower curtains around the shelf area. They have killed pepper and tomato seedlings before when they get in there.