How To Grow Tomatoes Tip 4 - Fertilising for the Home Gardener

Starter Fertiliser

All plants enjoy substantial amounts of organic matter – manure or compost in the soil. Organic matter holds nutrients in the soil so that they are not lost through leaching. It increases the amount of water your soil can hold as well as microbial activity in the soil, encouraging earthworms and creating a wonderful healthy soil system that produces nice sweet tomatoes.

Compost in the soil takes time to break down and release its nutrients– often up to 2 – 3 months. This means that if you want to use compost alone, it should be dug into the soil at least a month before you wish to plant your tomatoes.

It often helps to add a bit of fertiliser (even if you have used compost) at 5cm (2 inches) below and 5cm (2 inches) to the side of where you plant your seedling. If you put fertiliser directly in contact with the roots you will burn them and your tomato seedling may die or its growth be retarded.

Understanding Fertiliser Units

All fertilizers are generally described by their analysis. This usually consists of 3 figures that respectively label the percentage of Nitrogen (N), Phosphorus (P) and Potassium (K) in a product.

The sequence of N, P and K never changes. However in the USA these units are designated as N - P2O5 – K2O whilst in other countries (such as Australia) the units are N-P-K.

P2O5 means phosphate in the oxide form, as opposed to phosphorus (used in Australia) and K2O is the oxide form of potassium whilst in Australia only K or potassium is used.

You will find full details about fertiliser use (what to put on, when to put it on, how much to put on and how to apply it) in How to Grow Juicy Tasty Tomatoes. The fertilising chapter also contains valuable advice and photos on recognising and correcting nutrient deficiencies.