Is THIS brand & contents of potting mix okay?

[arlinek]

Home Depot did not have the Pro-Mix several have suggested. But, they do have potting mix by Super-Soil, listing the following ingredients. Is this okay for DIY earthboxes?

Ingredients


This product has been certified by the Mulch & Soil Council to conform with quality and labeling standards. Gardeners are assured of a quality product. Read more about the Mulch & Soil Council.
Every bag contains a blend of pure organic materials, plus the natural and traditional fertilizers plants need:

• Ground and aged fir, pine, and redwood bark, and high-quality compost combine to keep soil aerated and facilitate proper drainage.
• Nitrogen for helping plants grow and stay green. There's quick-release nitrogen that goes to work fast. And slow-release to keep feeding for up to 90 days.
• Phosphorus to establish strong root systems while stimulating flower, fruit, and vegetable growth.
• Potash to increase resistance to diseases and cold temperatures. Contributes to overall plant vigor.
• Iron for the prevention of chlorosis (yellowing leaves).
• Vitamin B1, recommended by gardeners to prevent transplant shock.

Plant nutrients come from urea, ureaform. triple superphosphate, ferrous sulfate, sulfate of potash, and gypsum.

[Sherry_AK]

I'd think you want a potting soil rather than a landscape soil. But I'm sure someone will be along who is an expert in such matters.

Sherry

[sirtanon]

I've used Supersoil in containers.. it's good stuff. Rich, healthy stuff but not TOO loaded with extra nutes. I say give it a go.

[Earl]

I've been using the Lowe's brand potting mix at $5.95 for 2 cu.ft. a bag. I bought all they had, about 10 bags.

[CLa]

Just watch that slow release stuff, sometimes it can all release/

[Joel5000]

Pro-Mix is hard to find in California. I use SuperSoil in all of my containers, but I add lots of perlite to try to lighten it a little bit, otherwise it tends to compact.

Also, it tends to vary a little bit from bag to bag. Its usually a nice consistency, but the occasional bag has bark that is a little bit too big for my liking.

[arlinek]

Thanks everyone; I ended up taking it all back, calling Earthbox Co. and getting their recommendation. They now say that Miracle Grow is fine to use, but I made sure to buy the one that has predominantly the peat moss & perlite or vermiculite. I actually found it at Costco!! It's the "Moisture Control" - with 3 mos. of fertilizer which is perfectly acceptable, per Earthbox company.

[CLa]

hmm, not sure if you want that, your already going to have plenty of moisture in an earth box. Be aware that if you have too much moisture near the top, then that strip of fertilizer, if you are doing it that way, as suggested with most earth boxes, then your taking a chance that the fertilizer will dissolve throughout your soil mix and nuke your plants. I suggest a non-moisture controll (no wetting agent) a very lightly fertilized or non fertilized peat moss based mix with perlite in it or added. Also the idea is that with a strip of fertilizer on top, and no fertilizer anywhere else, your roots know exactly where to go for their nutrients.

Basically the peat moss allows the water to wick up into the soil mix, but at the same time, it does not saturate the top of the mix where the fertilizer is. Even if the top was dry, your roots would provide enough moisture to thrive in those dry conditions and get the fertilizer they need up there.

Regardless, keeping your nutrients isolated to the top, and your water isolated near the bottom, your plant is not confused where it needs to go for its supplies. This is my theory and for now I'm stickin to it

[arlinek]

Well, CLa, I'm assuming that the "moisture control" in the Mir. Gro reflects that the primary ingredient is peat/sphagnum moss and then some perlite/vermiculite + a little wetting agent, which I was informed is exactly what the potting mix is supposed to contain. Egad, I hope so, because this was the 2nd lot of stuff I returned (heavy!!) before getting the recommended Miracle Gro (only 90 days of fert., which is also now acceptable). Here in So. California, I've been to and called over 10 different nurseries and could not find ANY large bags of potting mix with those main ingredients! Most all of them here are 50%+ with composted forest products, which is much heavier, I guess, and not the right recommended stuff - no moss. ALL the brands I wrote down from other Earthbox gardeners were not avail. here in San Diego.

[CLa]

Well.. First, it is always worth a try, whether that miracle grow is a good idea or not you will surely find out right? *chuckle*
Miracle Grow has been kind of a no no for me because the mixes usually have too much nitrogen per amount of potassium and phosphorus in the ratio. It should be reversed, you need more Potassium and Phosphorus than you do nitrogen by %.

Let me say though that they do not have pro-mix here either, but they do have the peat moss by the company that sells pro-mix. (premier) Since peat moss is realy what you want then your getting a better deal if you can put the mix together yourself. Really all you need is for one box is 70%+ peat moss, 10-15% perlite or vermiculite, and maybe a good handful of gardening lime. Then you could add anything else you want, little compost maybe. But this peat moss is sold at both Lowes, Home depot, and walmart here. So seems liek they would have it there.