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pH and NPK Values Explained

Gardening is NOT rocket science, but it is also not something that happens naturally for everyone. Yes, some people have a green thumb, but some of those same people jealously hoard the information that makes them so successful, often just so they can have the best yard or garden on the block! Don't be mad at them because they can do what you think you cannot! Get even instead and read up on how to make your garden grow! It only takes a little bit of knowledge and a few invaluable tools, such as one of our inexpensive home soil testing kits, to make your dream of having the most beautiful garden spot a reality. You are welcome to hoard this information if you so choose, though we think the neighborly thing to do is to share our site with everyone you know.

The first understanding you should have is just exactly what pH is and what it means. Most of you probably don't know that ‘pH' actually means ‘potential (or power) of Hyrdrogen'. (That's okay, I didn't know either!) Simply stated, it is a measure of the acidity or alkalinity of a material when it is dissolved in water. The material we'll be talking about is your soil. A pH value of 7 is considered neutral, while values less than (<) 7 are considered acidic and values greater than (>) 7 are considered basic, or alkaline. Most plants are able to withstand a wide range of pH levels, but if you are gardening organically, then the ideal pH level will be 6.5. Our article, Soil Testing 101, will give you a much more detailed understanding of pH, the importance of testing your soil and how to adjust the pH of your soil. An inexpensive, easy-to-use soil tester will give you the current pH and allow you to monitor the pH of your soil regularly, as the amount of rain and other environmental factors can change the pH.  

The second most important measurement to know is actually more than one, though it is sometimes expressed as the NPK value. N=Nitrogen, P=Phosphorous and K=Potassium (Potash). These three nutrients are the most important to understand and provide for the vitality and performance of your garden plants. These are also the three numbers that you will see prominently displayed on any bag of fertilizer and are an indication of the percentage of that nutrient in relation to the amount of the fertilizer in the bag or container. These values are uniformly listed in N-P-K order. Also keep in mind, that one is no good without the other nutrients to support your plants' growth. As in all of life, balance is important!

Nitrogen is the first major element that will cause your plants to grow strong and to mature quickly. Nitrogen depletion may first appear as discoloration of older leaves but then can advance in detriment, eventually causing the death of your plants. A nitrogen rich environment will produce healthy, green foliage and is directly responsible for the overall size and vigor of your plants, while a nitrogen depleted environment will result in stunted, yellow growth with even the new growth being weak and spindly. Needless to say, your plants cannot survive and produce well without it! A simple soil tester can quickly and accurately tell you how much nitrogen your soil has. If your nitrogen levels are fine, then you don't have to add itthat saves you money and time!

Phosphorous is the second essential nutrient that you will want to measure. Phosphorous is absolutely necessary for photosynthesis and enables the transfer of energy throughout the plant. The highest levels of phosphorous will be used when seeds are germinating, while the seedling is growing and while flowering is occurring. Phosphorous is also essential to boost your plants' resistance to disease and in order to grow strong, healthy root systems. An electronic soil tester can most quickly determine the levels of phosphorous in your soil, though some gardeners prefer to use a complete, hands-on home soil test kit. A phosphorous deficiency may show in mature leaves on a uniformly smaller, stunted plant; they may turn dark green. Though green is normally good, when the plant appears to be stunted and is ‘unnaturally' green, you may want to pull out your handy-dandy soil test kit and check the levels of phosphorous. Some foliage will also display purple or brown spots.

Potassium, or the K in NPK, prevents excessive water loss during dry periods, helps your plants to withstand cold temperatures and additionally aides their resistance to disease. Potassium, also called Potash, helps your plants to make the optimal use of light and air by increasing chlorophyll and regulating stomata (pores) openings which are used for gas exchange in plants, kind of like a human's respiratory system. If deficient, plants may grow the tallest and appear otherwise healthy, but older leaves will turn yellow between the veins followed by whole leaves turning dark, yucky yellow and dying off. You may also have a potassium deficiency if flowers drop before the fruit starts to develop, as this is when potassium levels are most important. High soil salinity can also block potassium. 

So, now you knowat least about pH and NPK. In addition to knowledge of these fundamentals, you of course need water and sunlight. Most vegetable garden plants will require plenty of sun and consistent moisture, while decorative annuals, perennials, grasses, shrubs and vines will have varied requirements. Amazingly, there are affordable moisture and light testers as well, all designed for the home gardener to enable you to grow your gardens just like the professionals (or your neighbors) do!

One Response to “pH and NPK Values Explained”

  1. […] Organic All Season Lawn Food – This all-purpose lawn food has an NPK* of […]

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