Greenery on walls can reduce a buildings heat loss by 30%, improve air quality, help absorb sounds, and can even reduce a cities temperature, so it is no wonder so many places are considering them.

Here are two options I think are interesting:

Vertical Meadows:

There is a bit of a terminology game here. Verticals gardens are sometimes found in wealthy office buildings, but they do nothing for local eco-systems and are often non-local tropical varieties of plants. Even for those found outside, the plants are often picked for appearance alone, instead of what would help local biodiversity.

In comparison, vertical meadows have a different goal. Vertical meadows (started in London, England) are outdoor vertical greenery walls that uses locally-grown native and seasonal plants, ensuring year-round options for wildlife like pollinators and birds.

The main problem with these setups is that they tend to require watering systems, which (even if rainwater collection is installed) can be rather costly.

More Info:

• https://youtu.be/Qyi_7HCVoPM
• https://youtu.be/OXUYZdfqq1Q

Moss Walls:

Companies like Respyre use upcycled bioreceptive concrete and a moss coating encourage moss-growth on any vertical surface without risk of damaging the buildings. Other companies(such as Green City Solutions) grow panels of moss, which can then be installed like tiles.

Due to moss being so inexpensive to incorporate, it is becoming a popular option.

For added benefits, moss is drought tolerant to a point, and can absorb 6x more C02 than other plants. Moss is basically a living filter, and can even filter arsenic out of water.

More info:

• https://youtu.be/cE02cQIVSAs
• https://www.youtube.com/watch?v=7tYG3MepUu0
• https://www.youtube.com/watch?v=7tYG3MepUu0

However, moss can be hard to grow commercially(mostly due to the fact that they release spores instead of seeds), so many of the mosses people buy, especially those used for craft supplies, are illegally poached from the wild. If a little is left behind, moss typically can regenerate, but many harvesters simply roll up huge blankets of moss, leaving nothing behind. It is estimated that the mosses can take 10-20 years to grow back.

So, please research where the moss is sourced if you plan on buying any. If the company does not grow it themselves or does not mention where they source it, do not buy any.