Nitrogen, Phosphorous and Potassium Every fertilizer product will include a “guaranteed analysis” depicted as three hyphenated numbers (10-10-10, 14-7-7, 34-0-0). These numbers represent the percentages of nitrogen, phosphorous and potassium, or N-P-K, in the container.
Be a Label Snob
The three-digit NKP number (nitrogen, phosphorous, and potassium) on the bag shows you the nutrient value. A bag of soil that is 20-20-20 will have double the amount of nutrients as a bag that is 10-10-10, and is better value for your money!
It's important to note that the Nitrogen, Phosphorus, and Potassium numbers on your fertilizer are percentages. For instance, a bag labeled with “23-3-8” will contain 23% Nitrogen, 3% phosphorus, and 8% Potassium. Together, these percentages show the fertilizer's “N-P-K ratio”.
Soil pH measures the acidity or alkalinity, and pH levels will range from 0-14, with <7 indicating an acidic pH, seven a neutral pH, and >7 a basic pH. The pH scale is based on a logarithmic scale, meaning the difference from a pH of 6.0 is 10x more acidic than a pH of 7.
What is a 30-30-30 fertilizer good for? This fertilizer promotes overall growth so it's great for established plants and fruiting plants that need a balanced nutrient profile.
NPK 20 20 20 is a highly concentrated, balanced plant fertiliser. It contains equal parts nitrogen, phosphorus, and potassium. It is ideal for growing plants in poor quality soils as it provides a high amount of each of the three essential plant macronutrients.
The best fertilizer for plants largely depends on their specific needs. Generally, a balanced fertilizer containing equal parts nitrogen, phosphorus, and potassium (NPK) can provide essential nutrients for overall growth. However, it's crucial to consider factors such as soil type, plant species, and stage of growth.
Gardening magazine's trial of the best soil mixture for raised beds found that a blend of 50% topsoil, 25% coarse sand and 25% compost was best.
These numbers represent the percentages of nitrogen, phosphorous and potassium, or N-P-K, in the container. A 40-pound bag of 10-10-10, for instance, will contain four pounds (10% of 40 lbs.) of nitrogen, four pounds of phosphorous, and four pounds of potassium.
Soil scientists use the capital letters O, A, B, C, and E to identify the master horizons, and lowercase letters for distinctions of these horizons. Most soils have three major horizons -- the surface horizon (A), the subsoil (B), and the substratum (C).
Some growers prefer to use a high-phosphorus fertilizer, indicated by a larger middle number. You can also keep things simple with a fertilizer especially formulated for tomatoes – usually with a ratio like 3-4-6 or 4-7-10. Most importantly, don't over-fertilize. Too little fertilizer is always better than too much.
The three numbers on a bag of fertilizer indicate the respective percentages of nitrogen (N), phosphorous (P) and potassium (K) it contains. Bags sometimes also show the percentages of calcium (Ca), magnesium (Mg), sulphur (S) and some micronutrients.
Lightweight: The best soil has a low density and facilitates soil aeration. Good drainage: Soil for container gardening should drain water easily, holding just enough to accommodate the plant's needs. Nutrient-rich: Potting soils should contain the essential nutrients (nitrogen, phosphorus, etc.)
Potting soil vs. potting mix: Though these terms are used interchangeably, there is a difference. Potting soil may or may not contain soil, while potting mix is strictly a soilless medium. Potting mix is sterile, which makes it safer for plants because it doesn't contain pathogens such as fungus or other diseases.
In this manner, the first number is always the amount of nitrogen (N), the second number is the amount of phosphate (P2O5), and the third number is the amount of potash (K2O). Together, they represent the primary nutrients your plant needs: nitrogen (N) – phosphorus (P) – potassium (K).
After 6-12 months most bags of potting soil have lost some, if not most of their nutritional value, but they are still safe to use. It just won't have optimal food to feed your plants.
The three letters, N, P, and K, correspond with three numbers that indicate the percentage of each nutrient in that particular product. For example, a product marked 10-10-10 contains 10 percent nitrogen, 10 percent phosphorus and 10 percent potassium. A bag marked 20-20-20 containers twice as much of each nutrient.
While the basic peat moss, pine bark and perlite type potting mixes will work fine for almost all annual flowers and mixed potted plants, there are some crops for which specialty mixes might be helpful. The most common is potting mix for orchids.
The ideal mixture for plant growth is called a loam and has roughly 40% sand, 40% silt and 20% clay. Another important element of soil is its structure, or how the particles are held together - how they clump together into crumbs or clods. A loose structure provides lot of pore spaces for good drainage and root growth.
Excess soil moisture can reduce oxygen in the soil, damage fine root hairs, and render the root system unable to absorb water. Plants exposed to excess moisture show the same symptoms as plants under drought stress. The primary symptom of excess moisture is yellowing of lower and inner needles.
Pinching. Pinch out the growing tip on flowering plants—annuals and perennials. When you remove the tip, the next set of buds on the stem awakens, and two new shoots start to grow. By pinching out the tip, you get twice as many growing stems, which means twice as many flowers.
Potassium. To get good yields of tomatoes, runner beans, squash, chillies, strawberries and other fruiting crops from containers, you need to regularly add additional potassium (K). The easiest way to do this is to buy a bottle of tomato feed. Although called tomato feed, this will do the job for all fruiting crops.
High-nitrogen fertilizers are known for causing huge growth in plants, which is why many types are rich in nitrogen or include it as the main component. Fertilizers high in nitrogen will also restore bright green hues to your foliage.