Pick a day of the week...any day. We chose Friday and call it "Fertility Friday". Easier to remember.
Our objective is to be consistent in providing fertility to growing crops.
Be careful though, because more is not better.
We only want to provide the amounts of nutrients that are needed (in available quantities) and that can be used by the plant, or else we can create imbalances (which can make us feel like the wheels came off the wagon).
We have a number of tools we can use to get closer to the ideal fertility quantities.
First, there is a base formula for general fertility for most crops. Calcium to magnesium should be at a ratio around 7 to 1. There are also ratios for phosphorus to potassium and carbon to nitrogen.
We can also monitor pH, but a pH reading can be misleading for a number of reasons, primarily having to do with a disconnect between pH and nutrient availability.
Two lesser known tools for monitoring the effectiveness of fertility programs are plant tissue testing and conductivity testing. Both of these can provide measurements which can be compared over time to see the success or failings of nutrients that have been added.
And foliar applications are especially effective compared to dry fertilizers or nutrients added to drip irrigation.
But the important thing to remember is that crops need fertility and should be feed regularly...on Fertility Friday. :)