A while ago I wrote about Milk As Fertilizer and concluded that although milk would add organic matter to a garden, it was no ‘magic bullet’. Since that report I have spent more time looking at the subject of milk fertilizer and tracked down how this myth was born. It a thriller full of deception and lies. Today I will dig deep into this myth and uncover some surprising facts. Then I will review the latest research on the subject.
There are so many types of fertilizer it’s hard to know which one to use. Which NPK ratio is best? Is one brand better than another? Organic vs synthetic. Soluble vs slow release. This all seems so complicated, but in this post I will simplify the whole process of selecting the best fertilizer.
Everybody tells you that plants need to be fed. Thousands of gardening books and blogs confirm the fact. Fertilizer companies certainly continue to make you feel as if you are letting your plants down if you don’t fertilize. And most nurseries try to push their products at checkout.
I have good news for you. In most garden situations, you do NOT need to fertilize.
The idea that ornamental gardens need fertilizer is a big myth.
Fertilizing gardens is a popular topic and every gardening book and website will give you advice. There are thousands of products on the market claiming they are the best ones for your garden. The problem is that almost none of this information is correct. Most gardeners are wasting time and money on fertilizer they don’t need. Even worse is the fact that they are wasting a valuable natural resource and polluting the environment.
If you garden, please take the time to understand fertilizers. I know this is not a glamorous topic, but it is very important to the garden and the environment.
Read most organic books or blogs and they will tell you that synthetic chemical fertilizers are killing the bacteria and fungi, the microbes, in soil. Dr. Ingham and her Soil Food Web preach this same message. Stop using fertilizers because they kill the bacteria and fungi. My review of Teaming With Microbes found the same message repeated several times.
Does fertilizers really kill bacteria or fungi in soil?
Some people claim that the ‘salts’ in fertilizer do the damage, but anyone making such a claim does not understand what happens to salts in soil. I’ll explain this in more detail below.
In my post Fertilizer: Selecting the Right NPK Ratio, I explained that you don’t feed plants – you feed the soil. Your job as a gardener is to add missing nutrients to the soil. If the soil contains all the nutrients plants need to live – the plants will do well.
The answer to the question, what fertilizer do plants need, is very simple. They need any nutrient that is deficient in the soil. If your soil is not deficient of nutrients – you do NOT need to fertilize.
But how do we know which nutrient(s) is deficient in the soil? I’ll try to answer this question in this post. In order to do that, we need to better understand what nutrients do in the soil.
Plant nutrient is a term used to describe plant food. We all know compost is good for the garden, but most of the good stuff in compost is not ready for plants to use – it is not plant nutrients yet! Over time, the complex molecules in compost, like proteins and carbohydrates, will be broken down by microbes into smaller molecules and eventually they become nutrients.
In this post I will take a close look at the main nutrients used by plants. What are they? What happens to them in soil? The answers to these and other questions will help you understand the process of fertilizing plants better.
A lot of the stuff on the internet is garbage when it comes to gardening advice. I am not surprised about that since many people just repeat what they have heard and give it very little thought. Some garden writers don’t actually do much gardening – they are writers, not gardeners. I rarely believe information unless it comes from experts in a field, government sites or published research articles.
This post is about an information guideline on fertilizers and soil amendments which is published by a government source – one you should be able to trust. Unfortunately it is full of incorrect or misleading advice. Let’s have a look at some fertilizer gardening myths.
We eat 3 times a day and the food we eat provides all of the nutrients we need to live. The chemicals in food are used by our bodies to grow and maintain our body parts. The protein you eat helps build muscles. Carbohydrates provide energy that is used for all kinds of things such as moving, breathing, thinking and eating more food.
Most of the food we eat is in the form of large molecules such as protein, carbohydrates, DNA, and fats. Our digestive system takes these large molecules and breaks them down into smaller molecules like simple sugars and nitrates. Our bodies then use these small molecules as building blocks to build new large molecules. Our bodies are actually a very efficient recycling plant. We take food in, break it down into basic building blocks, and then use these building blocks to create complex body parts.
Plants differ from humans and other animals in that they do not have a digestive system. Therefore, they are not able to break down large molecules. Plants must start with small molecules like nitrate and phosphate and build the large molecules they need.
Most references say that the NPK values indicate the % nitrogen, % phosphorus and % potassium. They say this, not because it’s true, but because it makes it simple to explain fertilizer concepts to the general public.
What does NPK really mean?
In past posts I have talked about some of the benefits of compost. It improves soil structure and it adds nutrients to the soil. What about the other benefits like adding microbes to the soil, reducing diseases and eliminating the need for additional fertilizer? Are these real benefits or just gardening myths?
In my last post Compost – Is it an Organic Fertilizer, I concluded that compost was an organic fertilizer and that it adds nutrients for the garden. I’d now like to have a closer look at the compost fertilizer numbers, the NPK, to better understand how and when the nutrients from compost are made available to plants. This discussion will also uncover some interesting facts about reported fertilizer numbers for organic fertilizers.
