Herb plants live for a long time if they are taken care of in the right way. That said, there are times in all of our lives when we are not present to take care of our gardens. Vacations, emergencies, or other trips prevent us from being home to keep them alive and healthy. If you have an indoor edible garden, then make sure that your lights are on a timer. Set the timer to replicate the hours of the sun. This will keep them from drying out too much, and they will continue to produce while you are away.
Outdoor gardens benefit from irrigation systems. This is certainly true during the hot summer months. One method involves simply inserting a piece of PVC plastic piping into the ground in strategically marked areas of the garden. Fill the piping with water, almost to the top. The ground beneath your plants will become saturated with water, and as the plants use the water, the water level in the pipes will slowly go down. This is a great do-it-yourself irrigation system which does not over water your plants while you are away.
If you do need someone to come over to take care of your plants, then you need to leave very clear instructions regarding what to do. If they get certain amounts of fertilizers, then it is best to go ahead and pre-mix the fertlizer to prevent any confusion from happening. Leave specific instructions regarding watering and feeding times. Make sure to provide instructions for when the plants start to show signs of stress. Choose a reliable person who has experience taking care of plants, and you will thank yourself over time. As long as you prepare, you do not have to worry about your home garden while you are away.