This stuff is supposed to work well as a medium for growing plants in.

I'm told it is acidic and will work well for strawberries, blueberries and other acid-lovers.

For non-acid lovers (most garden fruits and vegetables), one would assume it will work better if the pH is raised to something like 6.0 or 6.5.

I'm thinking of dumping this material into raised beds and using some to fill 5 gallon buckets for growing plants in.

What kind of lime should I use?

How should I apply it?

(Mix it in water and then dump it on so it will percolate through the growing medium? Mix it into the growing medium and then water? Something else?)

Any rough guides as to how much?

Obviously how much depends on the current pH. I'm thinking I'll buy a pH meter and use it to measure the current pH and then the pH as I mix in the lime (although that could be tricky as the lime probably be very non-uniformly mixed in at first).

If the current pH is 4.5, any rough guide as to how much per cubic foot of material (or per gallon or whatever)? What if it's 5 or 5.5?

What is a good pH to target for my non-acid loving plants (e.g. good average for tomatoes, potatoes, watermelon, beans)?

Is there any other good advice or helpful information anyone would like to share?

If not mixed in well will form clods of itself. I've crushed it later as I find the clods in the beds especially where I had existing plants growing, so just sprinkled it then covered with mulch.

Container gardening is tricky especially with a soil more suited to growing acid loving plants. Might be best to use a container soil for the buckets.

A good test crop would be beans or squash this summer with lettuces and spinach in the shade of the other plants. Consult someone in your area about what to plant now.

I noticed no one stepped up with a suggested rate, and I don't know how easy it is to determine that. Every soil would be different depending upon its composition. I would think someone smarter than me could take a wild guess just to get you in the ballpark though.

This stuff might be OK for containers IF the pine bark is coarse enough. The problem with containers is aeration/ compaction/drainage which is why good potting mixes have coarse material in them.

Compost usually has very good mineral availability, which is why I though the Ca vs. Mg question is less important than the starting and ending pH.

One goofy thing I saw on a how-to site suggested adding 20% lime to your potting mix to grow tomatoes! I don't know what that dude was smoking...

The main gist is that the base exchange should be saturated to 85% Ca.

Carbonate grabs a hydrogen from water forming bicarbonate and leaving hydroxide (OH-) which raises the pH.

The carbonate system is capable of reaching pH 8.3 on the top end, so if you add too much, you can overshoot the pH 6-7 range where vegetables are happy.

FWIW, pine bark fines are a consistent ingredient in better quality potting mixes and generally seldom require any liming to offset acidity. The vast majority of plants prefer to grow in slightly to moderately acidic soil, including nearly all veggies, so you may be making more of an issue of this than is necessary. I'd be inclined to want to know if the pH is instead adequately acidic for the blueberries. The acid potting mix we sell - bark based - has both peat and cottonseed meal in it to boost acidity.

Generally, the recommendation is 1/2 to 1 cup per plant (6-8 oz), worked lightly into the soil.

I do see your point though, gg. If the ingredients don't appear to be highly acidic, it does make you wonder.

I would ask the supplier specifically what the pH is.

It's also been my experience that soil pH and what creates it or changes it and to what degree is one of the most misunderstood of any soil topic. I wouldn't necessarily take anyone's word of what was what in that regard.

Cottonseed meal is primarily a fertilizer or nutrient source, typically included in organic ferts intended for acid lovers because of its ability to help acidify. But relying solely on cottonseed meal to lower soil pH is not an efficient or practical method, however can and does help when you are dealing with a container or potting soil.

The bulk of the modification done on any GMO'd crop is for disease, insect or pesticide resistance. For cotton, it is primarily insect resistance - the lack of need to spray insecticides is generally considered by most to be a good thing. Also cottonseed meal - like any other organic fertilizer - needs to go through a process of mineralization before they can be presented in a plant-accessible form. It is hard to consider that with all the necessary decomposition or consumption by soil organisms and the entire photosynthetic process some sort of deadly Frankengenes are going to come back and haunt us. Especially in the concentrations one would normal employ.

Lets stay within context here :-)