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You'll use it in minute quantities, so it won't affect the aeration/drainage of your soil to a significant degree. The chemical formula for the product is NaK2Ca5Al3Si21O706H2O. The manufacturer says it contains Potash(K2O): 0.2% (which needs to be adjusted for the O content, so it really only contains .167% K), Calcium (Ca): 1.8%, Magnesium (Mg): 0.5% Chlorine (Cl): 0.1%, Sodium (Na): 0.1%. In thinking about this, I can't see where the Mg is coming from because it's not in the formula. Even if it did have Mg, both Mg and Ca are ion the lime that is already in your soil, so that fraction is redundant. Cl and Na are virtually never going to be deficient in container media, and K is supplied in your fertilizer. Essentially, I'm saying that you are depending on this product supplying trace elements that are not present in sufficient amount to allow them to be listed under contents as even present.
Because it is insoluble (ground rock) it is probably going to be (practically speaking) unavailable for uptake in container media. I think that if I was looking for a source of trace elements, that I would use something like Micromax, STEM, or Earth Juice's Microblast. If it's the K you're after, Dyna-Gro's ProTeKt 0-0-3 is a superior choice, and it supplies the silica contained in the Azomite in soluble form so your plants can actually use it.
In short, it won't hurt anything, but don't expect any kind of noticeable results.
Thank you, tapla. I wish I had waited and posted in this forum before I bought it. :-(
No problem. It wasn't very expensive. I won't use it in my container media.
Thanks so much for your advice.
I use 1 part sphagnum moss, 2 parts finely ground pine bark and about 1 part perlite. Could you suggest any improvements? Do I need to add any trace minerals?
Any advice would be much appreciated.
I think you'd do better if you at least doubled the bark fraction in your soil. I have found 5:1:1, bark:peat:perlite a very good starting point & you can +/- the peat & perlite to get the drainage/aeration you prefer.
Whether or not you need a source of the minor elements depends on what you're using for fertilizer. Want to share that or explore that issue so I can opine? Remember to include lime when you make your soil. Most soluble fertilizers do not include Ca or Mg, and the lime supplies both while raising pH to a more favorable level.
Thank you so much. I will increase the pine according to your suggestion.
I use Osmocote. 19-6-12, lasts 6 months. Would you recommend something else?
Please tell me exactly the type and amount of lime to use.
My container plants do really well but I'm there's much room for improvement. I really appreciate your help.
Use dolomitic (garden) lime at the rate of 1 level Tbsp/gallon or 1/2 cup/cu ft. Dolomitic lime will have both Ca and Mg listed as the primary fractions of the product and the Ca content should be 2-5 times greater than the Mg content.
Yes - media pH is far less important in container media than it is in mineral soils. If you want to keep the pH low anyway, simply use CaSO4 and MgSO4 as your Ca and Mg sources (gypsum and Epsom salts) instead of lime. They have almost no impact on pH. Use the gypsum @ 1 tbsp per gallon or 1/2 cup per cu ft of soil when you blend it; then add 1/4 - 1/2 tsp Epsom salts to each gallon of fert solution each time you fertilize.
Most of the lake MI shore is zone 6. I live on the shore of Saginaw Bay (Lake Huron), so there is a few square miles of a solid zone 6 in the middle of a sea of 5.
When gardeners ask where I live, I often say, "I live in the crotch of MI at the bottom of Saginaw Bay." I live just below the crotch formed where the thumb meets the mitten. You can see it's zone 6 on the USDA map.
Mmhmm - you asked "... how many 39oz Folger coffee cans it would take to make 1 sq. foot of media." and I assumed you meant 1 cubic foot, and replied "24.6". Is there something I missed? "KDW" is you. ;o) The 39 oz was a volume measure and not weight, right?
I was planning to add the gypsum and epsom. I grow quite a few rhododendrons and conifers and worried about using the lime. I worry about my rhododendrons. I don't know enough about all this yet. Do you think the mix with lime would be OK for them?
Now that you say the epsom has to be added to the water instead of the mix I guess I would rather use lime. Will the epsom not be effective if added to the mix?
I hope I'm not confusing anyone. This is great information. There is very little in books about container mixes or if there is it's too vague. In my experience anyway. Is there a book about all this that you would recommend also. The stickys at the top of the forum were very informative. I had read somewhere else that a tall deep pot drained better than a short wide one but you explained it really well.
Also. I don't know how much mix I actually make each time. I've been throwing in a couple of small handfuls of timed-release with each batch and it seems to be OK.
I guess I'm looking for a standard measuring scoop that I can use to make exactly 1 gallon or 1 cu. ft. of mix. Any suggestions on that?
Epsom salts is extremely soluble & is quickly flushed from the soil, at about the same rate as soluble fertilizers, so it needs to be replenished frequently. It's about 125x more soluble than the lime fraction of dolomite or gypsum, which is why it should be added on a regular basis, instead of being incorporated into the soil when it's made.
To make a gallon of soil, you'll need about 5-6 quarts of ingredients. Based on 6 quarts and the 5:1:1 ratio, you would need a container that held about 27 ounces so you could take 5 scoops of bark + 1 scoop each of perlite and peat. It's not rocket science. You don't need to be that precise. ;o)
If you're using CRFs, you'll be in the right ballpark if you add 1 tbsp/gallon of soil or 1/2 cup/cu ft.
No prob. Thanks. Just wanted to be sure. But I kinda like the idea of adding a handful of manure. Just for trace elements? I have a virtually unlimited supply of goat manure. Above you recommended these: Micromax, STEM, or Earth Juice's Microblast. Do you use any of these or nothing at all in the way of trace elements? I've been trying for years to find answers to these questions. Thanks.
I use Micromax and STEM. I don't use manure because it breaks down very quickly and clogs soil pores. It doesn't add anything you can't get from a micronutrient supplement or soluble fertilizers like Foliage-Pro 9-3-6, MG/Peter's/Schultz 24-8-16, MG 12-4-8 ... and w/o the weed seeds. ;o)
Remember, growing in containers is very different than growing in the garden, and much of what works well in the garden is best left there.