Return to the Vegetable Gardening Forum | Post a Follow-Up

any info on potash application rate

Posted by thefarmguy 4/5coastal b.c. can (My Page) on
Tue, Mar 24, 09 at 20:11

hi, have a question that i wonder if someone might be able to share some ideas with.....i have inherited several 50 pound sacks of potash,,,,on the sack it says "Soluble Fines,...sulfate of potash for solutions and suspensions....0-0-50, soluble potash 50%, combined sulfur 17%,,,,all nutrients derived from sulfate of potash" so i have looked at these bags for a few years now not wanting to use them as i do know that potash can be just as harmful as helpfull if used in too high of concentrations,,,i do understand that it is intended to be mixed with water and used in a hydroponic or folar aplication. Does anyone think i can till this into the soil prior to planting... folar spraying is just too time consuming for us. it is in a fine granular state so i thought perhaps applying it with a lime/fert. spreader(backyard lawn style) and then tilling it in...anyone care to take a guess at what rate of application to use. thanks for any info

Follow-Up Postings:

RE: any info on potash application rate

Hi Farm Guy,
I have a bag of Sulphate of Potash that says it can either be dug in or used as a foliar spray, so I don't think applying it dry will be any problem. I've certainly used it in both ways.

Mine is 40% potassium, and the application rates are (converting from metric measurements) 1.5 ounce per square yard as a base dressing or 0.5 to 1 ounce per square yard as a side dressing for established plants.

I've also heard from a well-known gardener with sixty-odd years experience of sulphate of potash being used with blood and bone to create a general-purpose organic fertiliser, to prepare beds and as a mid-season side dressing. I've seen rates of 2 cups potash per bucket of blood and bone mentioned, but also 1:10 ratio so I don't know what's best there.

Your application rate would probably be a little lower than mine because your stuff is a slightly higher % potassium.

Are you treating a potassium deficiency, or are you balancing it with N & P for a fertiliser?

RE: any info on potash application rate

thanks ausbirch,,,yes i am hoping to use it as fertilizer, the land i intend to use it on is pretty tired, and not nice valley bottom in the first place, however we are working on long term improvement, with winter cover crops and composted goat manure, it still needs a bit of help to produce quality veggies on it while the soil transition takes place(hopefully) I just have been looking at those sacks and could not stand the thought of them going to waste, thanks again

RE: any info on potash application rate

Sounds like combining it with blood and bone could be the go, then. Or whatever sources of N & P are cheap and convenient to get.

Not sure you need to spread it around on its own unless you have reason to think you might have a potassium deficiency (I think sandly soils that get a lot of rainfall are especially prone to K deficiency through leaching. Not sure if this describes your land).

Since you have bags and bags of it, another thing you can do with it is apply it as a side-dressing or foliar spray at flowering time to help with fruit production. I either sprinkle it on the ground, scratch it in a bit and then water, or if I can't be bothered moving the mulch back I dissolve the stuff and apply as a foliar spray.


RE: any info on potash application rate

An "old farmer" guideline or tale on potash application is a 1 lb. can spread over 100 sq. feet.

But I have to say that a good safety recommendation is to have a soil test first and whenever this question comes up on the Soil forum here that is the first thing recommended. Simply because, like lime, it can alter your soil pH so easily.

Skew the soil pH too far to the alkaline side and all the nutrients in the soil can become unavailable to the plants. Got any idea what your soil pH is now?


RE: any info on potash application rate

hi dave, the areas i have tested last year seemed to be between 6-7 samples taken about 4mnths after they had been limed in the spring, we do get pretty hefty rainfall here(70 inches or so), most everything gets well washed over a 12mnth period. the land involved changes dramaticly from one area to another.(5 acres+or -) the "old farmer guideline" is not far off 1.5 oz to the sq. yd. thanks for the info.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Vegetable Gardening Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here