I thought I posted this on the gardenweb forum. Now it's houzz? Had to sign up for a new user name. Anyway soo - you can get the Naked Gardener Compost or Debco Premium Potting Mix from Masters (closing soon). Course Perlite is from The Perlite & Vermiculite Factory Myaree (much cheaper than anywhere else). Sand I got from a bulk landscape place (lawn mix) but you can get 10 or 20kg bags of builders sand at Bunnings. Zeochlor is in the pool section at Bunnings. Rock Dust I got from the manufacturer direct somewhere in Bibralake (called Natural PK) but I think but you can now get a similar product from Waldecks (in Myaree at least). Waldecks also sell bentonite clay. I still want to try the gritty mix but getting my hands on all the materials has proved very difficult when I tried last year. I found a Queensland company that makes course DE (for mopping up oil/chemicals) but they didn't have a distributor in Perth. Nobody I could find has pine bark in the right size - and even if they did I'd have to by a cement mixer and modify it with a fine wire to screen it. Honestly, if an agricultural company were to produce the gritty mix and sell it in bags I think they'd make bank - even considering how long it lasts.

I spend a lot of time at the Container Forum, just happened to wander over here! I recommend you post on the Container forum and talk to Al (Tapla) and JAG (Justaguy). The first mix will definitely be frowned on, the second mix is preferable if those are your only choices...with 50% fines it may retain water longer than optimal but that depends on your particular microclimate. Ideally you should need to water every day, means the mix is well drained with good gas exchange and fresh oxygen to the roots daily, think of container gardening as a cross between hydroponics and aeroponics...if you find yourself only needing to water every 2-3 days due to moisture retention then you won't have an optimal root environment and best results possible. Good luck. Tom

Face it! Miracle Gro is just a commercial potting soil, albeit generally of reasonable quality. See one post above though for a demurral to that. The one thing that the Moisture Control product has, that others don't, is a measure of coir. That is, the fibrous outer husk of coconuts. And yes, coir does help significantly with moisture control. Be careful, however, as they do have another product with a similar name that has water-retaining crystals. If you like that, fine, just be sure of what you're getting. Moisture control! Now, what do we mean by that? The coir absorbs lots of water without becoming soggy and then releases it slowly as your plant uses it up. I've used it for several years as part of my repotting mix, to which I transfer young seedlings to grow until they are planted out. Using this mix allows me to water once a day without any worry that the medium will become waterlogged or dry out before the next day. I can do this right up until the plants are a foot high, a foot wide and drinking water like crazy. Then they have to be planted out. This is in a 32 oz. cup. I don't have any experience with container growing but I suspect that the same effect would occur in a larger volume as well. Your plants should do as well and maybe better. The principal difference, as far as I know, is that the coir is substituted for other materials, such as peat, vermiculite or perlite. It does hold and ration water better than peat and it has an advantage over vermiculite and perlite in that it is a natural plant material and will gradually break down and contribute to plant nutrition. There are other possibilities for accomplishing the same thing, though. For instance there are other coir products, some very expensive. Miracle Gro Moisture Control doesn't have very much. You could add more or make your own mix by getting blocks of ground coir and wetting them. These can be found at hydroponic dealers and are not very costly. A container-grown plant should do very well in a mixture of about 3/4 of good garden soil and 1/4 coir. That would also be a lot less expensive.

Draw a picture of a 4 inch square. You could fit a 4 inch circle into it. So a 4 inch square pot hold more area than a 4 inch round pot. Now, did you say how tall the pots were? Myself I prefer the sq. pots. Seems to be more stable and less chance of rolling away. Do the math; area of circle pi x diameter or 3.13 x 4 compared to area of square 4 x 4. Since 4 is greater than 3.13 so a square is greater than a circle. My head hurts now.