When it comes to watering, there are no standard rules. It is a understanding that depends on the type of plant, the soil, the weather, the time of year and many other variables. Fortunately, there are some averages we can use to start to figure out what to do.
Ultimately going through the above, lead me to choose to use drip irrigation. The one I use has the drips already inbuilt, which made it cost-effective and gave precise delivery.
It has also allowed me to work out how long I need to water my garden to the most significant advantage with little waste.
While I no longer grow vegetables in a market garden style, the lessons learned have translated across to my Permaculture Potager. Knowing that I need roughly 5L per square metre per day, in peak summer and that there is a dripper every 30cms, having 3 rows means 9 double holes. Each hole releases 2L per hour, so that is 36L of water per hour per metre. Some simple maths at this point shows me that to achieve 5L per sqr metre I only need to run the irrigation for 9 minutes per day in the heat of summer to give the garden what it needs to thrive.
Simple, efficient and shows the power of design.