The Rain Garden is a vertical garden, developed by urban greening firm Treebox, that gets rid of many of the conventional problems normally associated with vertical gardens. The problem with vertical gardens is that while they look really great, they require a high degree of maintenance that is often automated and requires a lot of power.
What's special about the Rain Garden is that it doesn't require any power and is watered using rainwater alone. Situated at Tooley Street in London, the garden makes use of rainwater collected in storage tanks hidden behind the plants. The system supplies water from tanks to plants using a special wicking rope, allowing the plants to absorb the water.
This is a unique way to enjoy vertical gardens whilst being eco-friendly at the same time.