It's often a dilemma as to what to do about watering plants when heading off for a vacation; should a friendly neighbour be left a key, or should the plants be saturated before you leave and then you hope for the best? Several products on the market could help with this problem. Water balls or globes can be planted into flower pots or containers and filled with water to slowly seep moisture into the pot.
Water balls are glass or plastic balls that sit on top of a spike. This spike is then pushed into the soil surrounding the roots of the plant. The balls can be quite colourful and are usually made from handblown glass, but some cheaper plastic balls are available. The water balls can self-water a plant, usually for up to two weeks before the ball needs to be refilled.
Several products available have the same function, but work in different ways. The Plant Nanny and Plant Minder products come as two separate parts. A terracotta spike is pressed into the soil, while a removable water ball prevents roots from being damaged by constantly removing the spike to refill with water. The Aqua Globe comes as one solid unit of a blown glass ball atop a blown glass spike. These tend to be the more colourful products, turning the entire ball system into a feature rather than just a convenience.
How They Work
The terracotta spike products work by simply using the removable ball to hold a reservoir of water, which slowly seeps through the terracotta spike into the soil, keeping the plant constantly moist. The all-in-one products work by releasing oxygen back into the globe once the soil has dried out, which triggers release of water down the spike into the soil; regulating water to the roots only as and when required.
The slow release of the water means that plants can be left to their own devices for a certain amount of time. This can be helpful when taking a vacation or for hard-to-reach plants such as those in hanging baskets. The direction of water straight to the root also decreases the risk of disease by eradicating any water splash onto leaves from watering cans or other watering methods. Plants are watered slowly, therefore reducing any risk of overwatering.
It's easy to forget about these self-watering methods. Periodically the ball needs to be refilled so the plant can continue to be watered. The all-in-one balls have a tendency to clog up due to the water filtering out through the bottom of the spike; therefore they need to be cleaned out every once in a while. All water ball products tend to be top heavy, with the volume of water stored in the balls; it's important that the bottom spike parts are pushed thoroughly into the pot to prevent them toppling over. This also means that this would not be an effective method of watering for shallow-rooted plants.