Gardeners have been using fertilizer for many years and everyone recommends a particular ratio for each plant type. The rose society suggests, “6-12-6 is considered a Balanced Rose Food, as it supplies the basic ingredients in proportions beneficial to roses on a continual basis.” For tomatoes Burpee recommends, “such as 10-10-10, or where the middle number (phosphorus) is larger than the first number (nitrogen), such as 2-3-1″. Which is it, a 10-10-10 or a 2-3-1? I guess they don’t really know?
If you look at fertilizer supplies at your local nursery you will find numerous products labeled as rose fertilizer and each one has a different ratio. The same for tomato fertilizer – each manufacturer has their onw formula. Fertilizer for house plants or orchids is just as bad.
Here is a fundamental question:
Do different plants need different fertilizer formulations?
Almost everything you have read certainly suggests this is true, but does the science support this? Or is it more correct to say that most plants use exactly the same ratio of nutrients? After all, the biochemistry of all terrestrial plants is very similar.
In this post I will try to answer the question, what is the best NPK fertilizer ratio for plants?