Honestly you'd be better off with straight potting soil rather than adding the compost. But...

Al's Mix is actually really cheap to make, and quite easy. Bags of bark are cheaper than potting soil ($3.50 for 1.5 cubic feet) and my local bulk bark place lets you pick up cubic yards for about $27. That would definitely be the way to go for you, since you're filling big pots. (My rule of thumb is "you always need a lot more mix than you think you do!)

It's easy to get overwhelmed by the big long thread, but here's what it distills down to: bark, peat, perlite & nutes.

Everything can be found at Home Depot. Look for "soil pep" bark and bales of peat by the potting soil. The perlite is by the houseplants. The fertilizer aisle has lime and osmocote. The only thing you won't find is the micronutes, but you can water with Miracle-Gro containing those. Be sure to pick up a big tarp & shovel for mixing if you don't have one.

Here's your proportions.
2 bags soil pep or other bark (or 4 5-gallon buckets)
5-gal bucket peat
5-gal bucket perlite
2 cups dolomite lime
2 cups osmocote

PS: To clarify: my Home Depots have small bags of perlite but also LARGE ones, 3.5 cu ft., in the houseplant section. They are not on the shelf but usually stacked next to it. Cost is under $18.

A 3 cu ft bale of peat costs about $10.

Hope that helps! Jenn

. . . can "practically be grown in clay." really doesn't apply to containers. Water movement and retention in containers is starkly different than in the garden and beds. I'm pretty safe when I say that any attempt to grow in clay in containers will offer angst and frustration as your brightest hopes.

There's no reason you can't use a good grade of potting soil - one that's made to be used in containers and will not compact too easily or hold too much water. I offer my posts because I've found that if you're willing to water a little more frequently, it's MUCH easier to grow in a well-aerated mix that's sure to remain structurally sound for a whole grow season and beyond, and it has always produced more vital plants for me. The 1:3:3 peat:potting soil:compost will almost surely hold too much water, too little air, and break down quickly.

I would look for a source of perlite in 3-4 cu ft bags, as it's quite inexpensive in those volumes. I'd also keep looking at various places, in addition to the big box stores, for the bark. In the end, the bark mix will end up costing probably less than half to make than the potting soil will cost pre-made. If you end up unable to find it (the bark), I guess you need to do what you need to do, but I would suggest that you simply amend the good potting soil with a fair amount of perlite, rather than trying to extend it with additional peat & compost. I'm quite sure that route would serve you better, Sean.

Al

seanseansean,

I certainly understand the lack of funds and while I have never been to Iowa, I have had friend drive through it and tell me it's a large area with nothing in it ;-) So, you might have some initial difficulty finding what you want.

There is an alternative that should allow you to use the low cost ingredients you have found with good success. Can you access a sufficient number of low cost/free 5 gallon buckets where you can simply cut the bottom off and set them on the ground (actual dirt, not a deck or patio)?

If you can do this then you are raised bed gardening using containers rather than container gardening. As long as whatever you put in the bucket makes contact with the earth below, it becomes part of the earth and your mix can then be soil rather than a soil-less mix better suited for container gardening. Having the soil in the bucket in contact with the soil below will take care of the drainage and aeration needs of the soil in the bucket.

wow, thank you for your quick replies. I will have to give home depot a closer inspection then i suppose.

is bark mulch the same thing as bark fines? I've seen pine bark mulch and nuggets and even mini nuggest but no such luck on fines.

I'll give my local nursery a call also to see if they can help me get these things in bulk to save a bit more. thanks again.

i was browsing the thread you linked and was curious if i the lava rock that is advertised as ground cover could be substituted somewhere into my mix to increase its longevity?

I'm not sure of the size of the rocks, the picture is just the bag.

It sounds like you should be thinking 'perlite' if you're concerned about expense. You should be able to build a very good mix with the container soil you originally referred to, pine bark in the appropriate size, and perlite.

If you decide to go with an inorganic component in your soil, other than perlite, size is pretty important. You'll want something in the 1/16 to 1/8" size for best results.

Al

One cost saving measure I'm counting on is to reuse Turface and lava rock which I use.

If you put the used soil in a wheelbarrow and run a hose into it until it overflows the peat & bark will float or be swirled out and the lava rocks & turface will be left at the bottom.

Has anyone tried this before with good results?

I doubt it would work too well, EM.

A better idea would be to track down screening material with 1/8th inch openings and sift it. Anything falling through goes into a ground bed and anything not falling through is perfect to reuse.

Sorry, should have said 1/16th inch opening instead of 1/8th inch.

Wow, you've gotten lots of great advice, Sean!

The lava rock I've seen in my area of the country is way too big for containers, and as Al points out, it's not going to save you any money. I did see "pumice" at the bulk bark place which is approximately the size of perlite. IF you were already going to the bulk place, you might save by substituting the bulk pumice. Otherwise - perlite is cheapest and the perfect size.

Re bark fines vs. bark mulch: nobody in my area calls it "fines" but they do all sell "fine bark mulch." And yes, this is perfect, IF you can determine what kind of wood is used. Remember it doesn't have to be all pine - it could be pine, fir, and hemlock, those are all ok. The reason I'm favoring the "Soil Pep" is that it's about the only bagged product I've found so far that's actually clearly labled as to what type of wood is in the bag!

I would say just try the original recipe as written because it's foolproof, cheap, and materials are easy to find.

Best of luck. I started my container vegetable growing with tomatoes - they are tremendously satisfying!

Jenn

yeah i have, thanks to everyone for their advice. I will be making a huge batch of the aforementioned mix.

Just curious, not for expense issues but more so for availability. my dad has a lot of oak sawdust because he is a carpenter and i was wondering if it could be incorporated in at all? I've heard of people using sawdust before but it was with a drip irrigation system.

a little sidenote to hijack my own thread but what would a bulk bark place be called? like a landscaping company of sorts?

Thanks again to everyone. I'm getting quite excited to transplant these little seedlings.

Sawdust in containers breaks down quickly, promoting soil collapse and nitrogen immobilization (deficiency), so it's generally considered undesirable. The N immobilization isn't as much of an issue if it's in the form of finished compost, but even then, I would use it very sparingly or not at all - possibly as replacement for the peat component in a bark-based soil.

You'd likely track down a source of bulk bark by checking with greenhouses/nurseries with growing operations or landscape companies. I'm able to buy at wholesale by the pallet from a wholesale grower supply company (Al-Par Peat Company) here in MI, and I find there's almost no difference in price between buying (bagged product) from wholesalers and picking it up at retail outlets (when you/I can find it) like Meijer, Home Depot, etc.

Al

I can't find pine bark fines! I live in central Cal and all the bark products I can find locally are derived from Redwoods. I can find Gorilla hair(shredded redwood) and fine redwood bark mulch. Please advise.
Thanks.

The fine redwood (a type of pine) bark mulch is what I used last year and this in the container mix. Seemed to work fine and it looks good if you also use it as a mulch on top of the container.

In the container I had hoped it wouldn't break down fast, being redwood, but after a season it's pretty broken down.

I went to dexknows.com and put in "bark" to find bark dealers in my area.

I had trouble finding the right things but think I found good subs. I had to buy the perlite in small bags and have never seen it in bulk or large bags in my area. I got a little excited when I thought I had found the right size mulch, but it turned out to be made of old tires or something, so I had to go with a larger size. You may have to really do some shopping in some areas. At least it makes a big batch and is not too expensive. Of course, I wonder how many pots is enough?

Good coir is hard to come by. 98% of the coir purchased in the US is obtained as by-product of the bruch and rope making industry in India and Sri Lanka. To make the fibers tough the husks are soaked in salt water. The salts are left in the coir dust that are packed and sold are alternative to peat. In the past there was no market for this waste and it sat in dump and got rained on. This leached the dust and made it a fine growing medium. However nowadays all the old dumps have been used up amd the new dust is not being given time to have the salt leached out before being shipped. So some product come with high ECs an low pHs.
Pls go to my website at www.densuventures.com and click on the research tab.
Let me know it I may be able of further help to you.
Jake

.... he says shamelessly as he continues to post dozens of self-serving commercials all over GW.

Al

I went to my local farm store. They had most of the ingredients I needed for a lot less than the garden shops and even WM. We don't have a Lowe's or Home Depot. I picked up one bag for half of what the garden shops wanted and $1.50 less than Wal-Mart.

I have found other gardener's are more than willing to tell you where they get the best prices on supplies.