They’re not the same thing, and they behave differently in soil.

• Potash fertilizers: These are labeled, standardized sources of potassium—commonly muriate of potash (0-0-60) and sulfate of potash (0-0-50, often with sulfur). The guaranteed analysis helps you apply a consistent amount of K to support blooms, fruiting, and overall vigor.
• Wood ash: This is the residue from burned wood. It usually contains potassium in variable amounts and tends to raise soil pH. Nutrient content is inconsistent, so results can be unpredictable.
• Practical tip: If you need a reliable potassium boost, a labeled potash fertilizer is typically a steadier option. If you choose to use wood ash, apply sparingly and consider a soil test to check pH and potassium first.

They’re completely different materials with different uses.

• Potash fertilizers: These supply potassium (K), typically as muriate of potash (0-0-60) or sulfate of potash (around 0-0-50). Potassium supports plant functions like water regulation, stress tolerance, and flowering.
• Baking soda: This is sodium bicarbonate (a kitchen product) and is not a potassium fertilizer. Adding sodium and bicarbonate to soil can affect pH and soil structure, and may not be suitable for many plants.
• Bottom line: If your goal is to add potassium, choose a labeled potash fertilizer and follow the directions on the package. Results can vary based on your soil and plant type, so a simple soil test can help you dial in what you need.

Both provide potassium, but they differ in accompanying nutrients and chloride content.

• MOP (muriate of potash, 0-0-60): Potassium chloride with a higher K percentage. It’s widely used and can be a practical choice for many plants and lawns where chloride isn’t a concern.
• SOP (sulfate of potash, around 0-0-50): Potassium sulfate with little to no chloride and added sulfur. It’s often chosen for situations where low chloride is preferred or when sulfur is beneficial.
• How to decide: Consider your plants’ sensitivity to chloride and whether sulfur would help. A soil test can guide you. No matter which you pick, follow label rates and water in after applying to help move nutrients into the root zone.

Those numbers are the N-P-K analysis: nitrogen (N), phosphate (P₂O₅), and potash (K₂O) by percentage.

• 0-0-60: Zero nitrogen, zero phosphate, and 60% potash (expressed as K₂O equivalent). It’s a concentrated potassium source.
• SOP example: Sulfate of potash products often read around 0-0-50 and may list additional sulfur, which can support certain plant needs.
• Why it matters: The analysis helps you compare products and match them to your soil test recommendations. If you’re targeting potassium specifically, a product with a high third number focuses on K without adding N or P. Always follow the application instructions for best results in your specific conditions.

A careful, measured approach can help you feed plants effectively.

1. Test your soil: Knowing your current potassium and pH levels helps you apply the right amount.
2. Pick a form: Granular potash is great for broadcast or spot applications; water‑soluble or liquid formats suit feeding during watering.
3. Measure and spread: Follow label rates. Apply evenly—avoid piling against stems or trunks.
4. Water in: Lightly water after applying granular products to help move nutrients into the root zone.
5. Mind plant type: Consider whether low-chloride (SOP) is preferred for your plants.
6. Safety: Store fertilizer dry and sealed. Keep out of reach of children and pets, and avoid application right before heavy rain.