Water your vegetables, preferably in the morning, until water flows from the bottom. During hot weather, plants may need watering two or more times a day. A sure sign they need watering is when their leaves become limp. If you have lots of containers, consider using an automatic watering system. One of the most common is a hose with smaller tubes emerging from it that can be placed into individual pots. Attached to a spigot, it can be programmed to come on at predetermined times, keeping your plants watered even if you're away. You'll have to monitor the system to be sure the intervals and length of time the system is on is sufficient for the conditions as summer wears on.