Don't feel like reading? Watch this video instead, it covers the exact same info.
Just as humans require different minerals, like iron and magnesium, in order to grow, thrive, and carry out their natural functions, so do plants. There are three major (macro) nutrients that ALL plants need, and as a grower, you must know what these are and how they affect your garden.
The three letters every grower must know are NPK.
What is NPK?
NPK is an acronym that represents the 3 most important nutrients every plant needs: Nitrogen, Phosphorus, and Potassium (which is represented by K on the periodic table). These 3 nutrients affect the overall health of your crops and determine where most of the growth is directed in your plants. Higher amounts of one mineral guide your plant to produce bigger leaves while higher amounts of another mineral guide your plant to produce bigger fruits. What good would it do you to grow a tomato plant with huge leaves and tiny tomatoes? None. This is why understanding NPK is important.
What Role Does NPK Play in My Garden?
Each nutrient plays a role in the overall health of your crops, and more importantly, where the growth of your crops is directed:
Nitrogen promotes vegetative and leaf growth. It is crucial in helping your plants build chlorophyll which allows them to photosynthesize (use sunlight to create "food" or energy for themselves). It promotes healthy leaf and steam growth. Leaves are what allow all plants to soak in the rays from the sun and send that energy to lower regions like the roots that don't get exposure.
So when you think of Nitrogen, think of leaf growth.
Phosphorus stimulates root growth, and flower/fruit development. Every fruit starts off as a flower, so the production of flowers is a necessity for fruiting plants. Phosphorus also supports the production of seeds and is very important in the early growth stages of a crop.
When you think of Phosphorus, think fruit development.
Potassium (K) supports the plant's immunity to disease and ability to withstand stress from the environment. Yes, plants get diseases too! They are just as alive as you and me. Potassium also supports the plant's ability to uptake water from the soil and contributes to the overall fruit quality and health of the plant.
When you think of Potassium (K), think immunity and protection.
Why is This Important?
Knowing how NPK contributes to the growth and overall health of your plants is important because it will help you determine what type of fertilizers to buy. All fertilizers show the ratio of NPK on the front of their containers. An example of the fertilizer I've used both at my time working on an organic farm and in my own garden is below:
You can see the NPK ratio of this product at the bottom of the bottle: 2-4-1. This means that this specific fertilizer has a ratio of 2 parts Nitrogen to 4 parts Phosphorus to 1 part Potassium (K). Based on what we covered above, this would be a beneficial fertilizer to use on a plant that produces fruits, like tomatoes or eggplants, because it is higher in phosphorus.
What Else Does NPK Tell Me?
NPK can also let you know whether your plant is receiving too much of one nutrient, or not enough. Plants will let you know what they need just like people do, and knowing how to "read" your plants is crucial in ensuring they are healthy and growing properly.
Not enough Nitrogen can look like your plants' leaves turning yellow or the growth being stunted (For example, it grew only 2 inches but won't grow any higher than that regardless of how much time passes). Too much Nitrogen can look like a plant with HUGE leaves, but tiny fruits, if any fruits at all. If you're growing tomatoes for example, a tomato plant that is receiving too much nitrogen will have big, beautiful leaves but super tiny tomatoes (if any tomatoes grow at all).
Not enough Phosphorus can look like your plants' leaves turning red or purple. Too much Phosphorus will also look like discolored leaves, but instead the leaves develop yellow "stripes" or become dark between the veins of the leaves.
Not enough Potassium (K) can look like think-skinned or small fruits and plants that are very susceptible to disease. Too much Potassium (K) won't display distinct visual signs in your plant, however, too much potassium can cause deficiencies in other nutrients that do show visual signs. This may look like leaves turning yellow between the veins, browning spots, stunted growth, curling leaves, or reduced root development.
Now that you're familiar with NPK, you've picked out the crops you plan to grow and got your seeds, and you know what soil you're going to use for your garden, there is only one more "pre-planning" activity to cover before we usher into planting season. Be sure to connect with us on Instagram and YouTube to stay updated!