NPK is a really common phrase and idea that you’ll hear a lot about in gardening. I’ll explain a little about what it is, before we talk about why I think it kind of sucks.
NPK is important to understand when it comes to fertilizer. Most fertilizers are spelled out based on what they contain for amounts of three nutrients— Nitrogen, Phosphorus and Potassium.
Here’s what those three elements do for plants:
Nitrogen: needed for leafy growth on plants and dark green colour
Phosphorus: needed for roots, flowering and fruit development
Potassium: overall plant health…helps with roots and top growth
Some gardeners suggest that in an ideal world, you would have your soil tested in order to figure out what nutrients are there in abundance and which nutrients are lacking. You can get little test kits from garden stores and places like Canadian Tire for less than $10 (however they only measure the N-P-K), or consider having your soil sent away to a lab that will analyze for more nutrients.
Once you know the relative levels of N-P-K in your soil, it then helps you to choose a specific fertilizer that YOUR soil needs.
HOWEVER, this is rather reductionistic thinking and why I’m not a super fan of ONLY NPK.
As a Naturopathic Doctor, we’re always wanting to support the whole vs simply component parts. This means recognizing that although nitrogen, phosphorus and potassium are very important for plant growth, there are many other nutrients that plants also require to grow well and to provide you with a ton of nutrients when they’re consumed.
Some better options to NPK fertilizer are more diverse in their support. Things like compost, worm castings, or a combination of support (think egg shells, coffee grounds, kelp fertilizer, etc) is what’s going to help your garden grow it’s best!
What have you been using on your garden to help grow food?! Is it well-rounded or just the standard NPK?!