How to water plants while on vacation is a common concern for all home gardeners. However, there are tools out there that can be utilized to ensure your plants, both indoors and outdoors, are cared for properly. You can get drip irrigation systems that come with timers or soil moisture meters, while more low-tech options include using old wine bottles as slow-release watering stakes or DIY drip irrigation systems that can be made out of plastic bottles. A garden olla, which can be made using two terracotta pots, is a historic way of keeping the soil moist and capable of keeping plants hydrated while away.