Organic Sources of Potassium for Your Lawn or Garden

Hardwood ashes are a popular “home-made” source of potassium.

Potassium is a very important nutrient for overall plant health. It’s involved in protein synthesis and in the flow of nutrients and water up and down the plant. Potassium strengthens plants against cold, heat, disease, and pests, and it’s the key ingredient in fertilizers labeled as “winterizers.”

If you’re looking to go organic, there are many ways to supplement your lawn or garden with potassium without using chemical fertilizers. Here are the most common sources of organic potassium:

Compost: Compost is full of nutrients, including potassium, especially if it is beefed up with banana peels and other fruit and vegetable waste. The potassium compounds in compost are water-soluble, which makes them readily available to plants but also likely to leach out of your compost pile over time.

Wood Ash: The original source of “potash” fertilizers, hardwood ashes can be used directly as a fertilizer (about a 5-gallon bucket per 1000 square feet) or added to your compost pile to increase the potassium content. Wood ash also raises soil pH, so be sure to do regular soil testing to make sure it stays balanced.

Kelp Meal: Available dried or liquid, kelp and seaweed offer potassium to the soil in a fairly quick-release form.

Greensand: Mined from ancient former sea beds and is rich in a number of minerals including potassium. It’s used both as a fertilizer and a soil conditioner, or it can be mixed with compost.

Muriate of Potash (potassium chloride): Mined from ancient deposits, this commercially available product can be used as natural sources of potassium, though the chlorine found in it can harm soil microbes.

Sulfate of Potash (potassium sulfate): More expensive than muriate of potash but safer, since it doesn’t contain chlorine. Not all potash products are considered organic, so make sure the product you use is approved by the Organic Materials Review Institute (OMRI).

Sul-Po-Mag: A variation of potash, Sul-Po-Mag is actually a naturally-occurring mineral called langbeinite (sulfate of potash-magnesia). Sul-Po-Mag is water soluble and convenient, although it shouldn’t be used unless your soil also needs sulfur and/or magnesium.

Granite Dust: Available from granite quarries, granite dust is a relatively inexpensive way to add potassium and tract minerals to your soil. Since it’s ground-up rock, this product is very slow to release its minerals and is not a quick fix.

Further Information


  1. I have seen your suggestion and it is good for the nursery and kitchen garden.
    I want to prepare organic fertilizer having 5-5-5 NPK. Please adives wich are the sources of ingredients for getting afore said quality organic fertilizer at competative price?

  2. A wood ash product that is commercially available is coconut palm ash. It can be bought either pearled or powdered. Powdered at 0-0-30 runs about $2.83 per pound in twenty-five pound quantities. Or, it can be bought F.O.B. south east Asia for $600.00 per ton. Please note there are also some OMRI listed potassium sulphates available.

  3. @Sekhar Basu say bro i have seen your comment, ive seen a few organic nutrient lines with the npk of 344 and 455, check out technaflora’s puravida, and then general hydroponics general organics line biobloom….. or u can make ur own mix like i do…… check out different websites that have what you want or make your own with what you can from stores…….. peace

  4. Thank You!! This is my year to focus on nutrients and making my own fertilizers. This provided a great start. It had alot of information in an easy to understand format. It’s a good base to refer back to as I sink deeper and deeper into the myriad of suggestions and advice on organic gardening.

  5. I used to know a guy that would cut up Bananas (peel and all) and smash them into the soil around his plants when it was time to for them to flower, then water over top of the banana-coated soil.

  6. Dude how much ash should be added to a Miniture/Bonsai ive got a 6 year old peach tree thats 30cm tall.. And i need speed in my plant.. It could help allot with the manipulating of the branches

  7. there is a organic fert calld maui moondust that is the best high potassium fert i have ever used. i have seen that now u can order it from their new web site at . great stuff. works like nothing i have ever used and its made in maui. free shipping too.

  8. I was wondering if I ground white rice up, would that be a good source of potassium? White rice isn’t great for human consumption but it appears that it is very high in this mineral.

  9. Hi,

    I make a organic liquid fertilizer from Fish emulation. I add Coconut husk powder as potassium resource. I need to improve this for different corps. Paddy, Cconut,vegatable,friuts etc. So I need to add N P K and others minerals according to the corp specification. Could someone help me on this please. I need to know what are the best resource for N | P | K. I am from sri lanka. please email me

  10. Please what quantity and the unit area are required for these organic potassium fertilizers? compost, wood ash, kelp meal, muriate of potash, sulphate of potash and granite dust.

  11. How planting plant to coconut husk powder? Are any other items will add to that?. otherwise is coconut husk powder enough to grow plant?. Give an some idea.

  12. Greetings,
    We raise and cross pollinate Hibiscus plants. I did not feed them for a long time but made my soil out of mountain dirt, rice husk and coconut husk. We have done ok with this but within the last 4 months have been using Miracle Grow (acid plant formula) and the results have been much better. In reading some articles I am intrigued by all the comments regarding Potassium. I live on the island of Cebu in the Philippines and have a great source of hardwoods available. I would like to know more about how to effectively make the ash and if there are specific’s I should know about…
    Thank you very much for this site!
    Regards, Brian Baumgardner

  13. We have Banana & pappaya plant’s we are growing in organic method we require some details for multinutrient to Plants. In what source we can prepare the multinutrient?

  14. The amount of ashes you would produce would be minimal and the green rubbish may not contain potassium levels found in sunflower ash not to mention the phosphorus and sulfur that is also available


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