When you're growing potatoes at home in a garden be sure to make sure the soil stays moist and when the soil that the potatoes are growing in becomes dry it's time to water the potatoes.
Potatoes usually need a good watering about every 4 to 5 days unless the weather is hotter and the soil dries out more often.
Give the potatoes at least 1 inch of water which takes around 30 minutes to water with a sprinkler or about 15 to 20 minutes with a garden hose.
I usually just set out a sprinkler and let the sprinkler water the potatoes and other garden foods and plants for at least 30 minutes.
I water in the morning before it gets too hot so that the plants do not get burnt and so that the water doesn't evaporate.