How Frequently Should You Spread Potash in a Vegetable Garden?



Like children, vegetables grow best when well fed. Fertilizers contain essential macro-nutrients, nitrogen, phosphorus and potassium — the N-P-K ratio displayed on the tag — and micronutrients, like manganese and calcium, in varying amounts for various kinds of plants and soil. Potash is a major source of potassium, which supports healthy cell development, root growth and fruit-bearing. It is possible to obtain several chemically invented and organically occurring forms of potash to supply your vegetable plants using the potassium they require.

Selecting Potassium Needs

Figuring your plants’ mineral needs is best done through soil testing. A soil evaluation, in the commercially available kit, or from a commercial laboratory, indicates naturally occurring amounts of nitrogen, phosphorus and potassium, together with other minerals like manganese and calcium. Testing using a pH meter will assess your soil’s acid/alkaline equilibrium, which determines how plants may absorb nutrients. Soils can differ widely from area to area and even neighborhood to neighborhood. Testing, together with information from your regional extension office or garden center, can direct you in addressing the specific needs of your garden soil.

Sources of Potash

K is the symbol used for potassium percentage content on fertilizer labels, to distinguish it from phosphorus. A 10-10-10 fertilizer provides equal proportions of nitrogen (N), phosphorus (P) and potassium (K). A high-nitrogen fertilizer, ideal for promoting grass and other leaf growth, has a ratio like 18-4-8. A 5-20-20 ratio is high in the iron and potassium. Besides balanced N-P-K fertilizers, potash is individually available as muriate of potash or sulfate of potash, using a 0-0-50 N-P-K. Ground dolomite stone is a good supply of potash. Commercially available kinds of fertilizer include organic fertilizers, compost and manure. Naturally available sources include compost, manure and wood ash. Exact quantifies of potash will vary in natural sources. Based on Hume Seed, for instance, potash content of hardwood ash may fluctuate from 2.8 to 8.6 percent.

When and How to Employ Commercial Fertilizers

In general, you must turn fertilizer thoroughly into soil when you prepare garden beds for planting. Meanwhile, the International Potash Institute recommends two programs in deep clay or other soils where a single full dose might be leached off by poor drainage. Avoid putting fertilizer in the bottom of planting rows, where it comes in direct contact with seeds or seedling roots. You can continue to encourage wholesome growth for heavy-feeding vegetables, like potatoes, cooking greens or corn, with side dressings of balanced fertilizer, in midseason or several times during the growing season. To side dress, put fertilizer in watering furrows as opposed to directly on or around plants.

Applying Natural Potash Sources

It is possible to dig natural sources of potash into the ground in early spring and late autumn as part of long-term soil enrichment. Natural mineral sources tend to release nutrients gradually, enhancing soil gradually. When you apply them outside the vegetable growing season, you avoid possible plant damage from the gain in soil salts brought on by excess potash. Burned hardwood ash can be a good supply of potash but is best implemented before and after the growing season. Forming potassium hydroxide in the presence of water, wood ash is a foundation for making lye. Advocates discount dangers of root burn pointing to the low nutrient content of wood ash compared with commercial fertilizers, but you could still prefer to accentuate your garden using wood ash in autumn, winter or early spring.

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