How often to water? Five year olds in full sun and heat year round.a
A general recommendation would be to deep water once a week during the hot dry summer and fall. But your plants may need more or less than than depending on the soil and growing conditions, and how you go about watering.
Superficial irrigation that only gets an inch penetration into the soil won't do it. You need to use a sprinkler or preferably a "soaker hose" to slow water for a couple of hours or more in order to achieve wetting of the top 6 inches of soil or more. If you mulch the soil surface with a 2 inch layer of compost, it will help to retain soil moisture for a longer period of time.
A soil moisture meter can help to take the guess work out of when to water.