As a rule of thumb - I always water once the sun has gone down so the droplets don't scorch the plant due to the heat of the day - but if overcast then it will do no harm

To be honest, watering is something that takes years to master properly.

The answer to your question depends on so many things....soil type, weather, how much organic matter in the soil, any shade or full sun, type of vegetable grown, how long they've been established and probably a few i've not remembered.

Plants such as Beans and Peas require lots of water, onions need less, root veg such as parsnips, carrots and beetroot tend to need more at the start until they're established.

As a general rule, if the ground's dry, i soak them at the roots, preferably in the evening....and i mean drench them. Light sprinklings tend to bring the roots to the surface to look for water, which then dry out if not watered.

Hi, welcome to GoY, I agree with Badfish entirely, little and often is no good at all, give them a good soak, then leave them alone for a while, and make them send roots down in search of water, {just don't leave them too long without water}, Derek.