On the one hand, you can place more robust plants in the garden. You should preferably find a shady spot so that they are not permanently standing in the blazing sun. Thus your potted plants automatically receive precious water from above when it rains. If you are only away for a few days, it is sufficient to place a full bottle of water upside down in the soil of the tub plant. The plant takes as much water as it needs. Or you use plant containers with water reservoirs.
If you go away for a long time, automatic irrigation systems are available, which can be used to supply water to lawns, hedges, greenhouses or potted plants and flower boxes as required, depending on the product. Combined with a Water Computer, the plants are ideally watered. A rain sensor ensures that on days with rainfall no additional watering of the plants takes place. With an additionally installed soil moisture sensor, irrigation is not started if the soil is moist enough. Such irrigation systems are not difficult to set up, but should be put into operation a few days before the holiday begins so that you can be certain that everything is working as you want it to.
Those who do not like automatic irrigation solutions can still fall back on good old neighbourly help. Especially if as many plants as possible have been moved outside, on a terrace or in the garden, watering is clear and easy for the neighbour.