Sulfate of Potassium- okay for organic gardening?

[ARgardener]

Alright, so my soil is quite low in potassium. I understand that muriate of potash is not suited for "organic" gardening due to it's chloride content.
People have suggested things like greensand (too expensive), worm castings (too time consuming/ expensive), and wood ash (too variable plus my pH is right where it needs to be).
I've seen sulfate of potash listed in some organic gardening sources, but not often. I'm curious, would sulfate of potash be a suitable way to raise my potassium without trashing my organic approach?

If it's fine to use, how often to apply? When to apply relative to planting time?

[henry]

This link may be of help to you.
http://www.protassiumplus.com/about-...m-plus/organic

[ARgardener]

Originally Posted by henry

This link may be of help to you.
http://www.protassiumplus.com/about-...m-plus/organic

Thanks. I can't really find their products for sale anywhere though. I did, however, find this product
https://www.amazon.com/10-Pounds-Pot...assium+sulfate

On the Alpha Chemical website; under the specifics for this product, "alternate names" lists Protassium+. This plus the fact that they're from the same city and both cite OMRI labeling leads me to think they are more-or-less the exact thing.

I think I may as well go for the product I linked- any objections?

[henry]

May even be from the same plant just rebranded.

[ARgardener]

Originally Posted by henry

May even be from the same plant just rebranded.

I've got the same feeling. I think I'll go ahead and order... I've got peas seeds coming up and those babies will be needing some K

[ARgardener]

Alright, so I've got my 10 lbs of Sulfate of Potash (0-0-50).
I'm curious about applying this stuff... is there any risk that it could "burn" seedlings or inhibit germination if applied directly to the seedbed? Or is this just a worry with nitrogen?

[henry]

100 pounds to an acre is common. 1 1/2 oz to a square yard is what I found for garden use not sure what the problems would be if you use to much.

[ARgardener]

Originally Posted by henry

100 pounds to an acre is common. 1 1/2 oz to a square yard is what I found for garden use not sure what the problems would be if you use to much.

I've got the amounts.. just wondering if it's safe for it to come in near-direct contact with the seeds

[RayR]

Originally Posted by henry

100 pounds to an acre is common. 1 1/2 oz to a square yard is what I found for garden use not sure what the problems would be if you use to much.

Potassium competes with Magnesium, using to much K can induce the signs of a Mg deficiency in the plant.

[henry]

Not sure what direct contact would do have only used it well mixed into a seed bed.

Some potassium sulfate is supposed to be approved for organic gardening, but some of it is not.

The AlphaChemicals kind claims to be approved for organic gardening, but I tried to check it out and I didn't find anything in my search to prove that it was. Nevertheless, I got some from them on Amazon and some from them on eBay. The eBay product, although less expensive, had dark particles in it in addition to the potassium sulfate. The Amazon kind looked very pure (and was very effective). I haven't used the eBay kind as much, but it seems to work. I'm not sure what the dark stuff in it is.

[RayR]

Originally Posted by shule1

Some potassium sulfate is supposed to be approved for organic gardening, but some of it is not.

The AlphaChemicals kind claims to be approved for organic gardening, but I tried to check it out and I didn't find anything in my search to prove that it was. Nevertheless, I got some from them on Amazon and some from them on eBay. The eBay product, although less expensive, had dark particles in it in addition to the potassium sulfate. The Amazon kind looked very pure (and was very effective). I haven't used the eBay kind as much, but it seems to work. I'm not sure what the dark stuff in it is.

Potassium Sulfate is mined from natural deposits. Difference in color of particles is due to the purity of the final product. Not going to make much difference in applying powder or granules to garden soils, but if you were going to use it in liquid form you would want a very pure solution grade powder.

I recommend potassium sulfate mostly for indoor use (for all kinds of seedlings and such), and for outdoor muskmelons. I'd rather use wood ash for outdoor tomatoes (if the pH weren't an issue), but potassium sulfate will provide them with potassium. If you've already planted, I'd use potassium sulfate. Potassium sulfate can also help to reduce the symptoms of transplant shock.

I like to use peat moss to balance the pH with the wood ash, these days. I'm not sure what it reads on a soil test, but the plants grow in it.