It makes plants grow and the fruits develop and taste good. If all your plants are in containers, a watering can should suffice. Soaker hoses can be placed in the garden and topped with mulch. Water should reach about 6 inches deep for optimum root growth. Use a trowel to measure how deep the moisture is penetrating.
Timing is also a key ingredient in conserving water and keeping plants healthy.
While the traditional rule is to water flowers and vegetables very early in the morning, that's often not practical. If you have the water on the ground, that's good. Mulch works in tandem with correct watering. It moderates the soil temperatures and reduces evaporation, particularly in hot summer weather. That's possibly due to the placement of flower and shrub beds out front, where mulch adds a finishing touch.