Nature's Living Wall, Fifty Species in Coquina Stone, Castillo de San Marco

Native plants play an important role in supporting worldwide biodiversity heritage, and offer an awesome opportunity to explore history.  Weaving history into present green roof technology is one of the most exciting aspects of touring historic places like St. Augustine, Florida.

I always love exploring the Castillo de San Marcos structure on the banks of St. Augustine inlet, just north of the Bridge of Lions.

Though not what you would expect, one of the many ways to learn about native plants on the fort park property is to 'look up'.  This week I spent several hours walking in the moat of the old Spanish Fort in St. Augustine.  Plants grow all over the rough coquina shell stone wall.

In my opinion the National Park Service has it backwards - they charge for going inside the fort but allow you to walk for free in the moat and around the grounds.  The moat is where you can see many, many native and other plants species growing in the coquina walls!

Castillo de San Marco, St. Augustine

As you can see in the above photo, most plants grow underneath the downspouts on the walls. Though the downspouts provide water primarily when it rains, they also collect dew and fog from surrounding areas and funnel the water to the plants.

Interestingly, learning about green roof and living walls plants from the fort offers insight into those plants that not only do well under the hot Florida sun and with no additional irrigation, but also the plants shed light on soil media composition.

Coquina shell and the limestome mortar have a quite high pH level.  High pH is usually one of the toughest issues to work with on green roofs and living walls.

If you are looking for native plant species that thrive and survive under harsh conditions such as; relentless sun exposure, salt spray, hot desiccating winds, heavy frosts, hurricanes without irrigation other than rainfall, then plan a trip to Castillo de San Marcos, or other similar stone structure.

It is amazing just how many different species can be found growing vertically, forming amazing living walls.  Park staff have identified over fifty different plant species growing in the coquina stone walls!  What an awesome living wall created by nature!

Samolus valerandi

Pteris vittata & 2 Cuban anoles

Wildlife seeks out plants, especially those providing resource benefit such as food or nectar or shelter.  Native plants are best suited at providing the most optimum level of ecological benefit to those wildlife endemic to an area.

In otherwords, planting native plants on green roofs and living walls encourages and supports native populations of insects, birds, reptiles, amphibians and other wildlife.

Many popular landscape plants used on green roofs may not offer the same level of resource benefit.

Learning about your local native plants broadens design capabilities for both green roofs and living walls.

Limestone & Coquina Walls are Harsh Ecosystems