Notes from Around Town: Green Walls!

I am sure that most of you have heard of green roofs, but have you heard of green walls? These pictures I took recently in Williamsburg, Brooklyn, of a new green wall on N. 4th between Bedford and Driggs. My boss lives in the neighborhood and she made the discovery one morning while walking her dog. She gave me the tip and I had to check it out.

I have been studying green roof technology here in New York City for a little while but this is the first I had heard of an exterior green wall here in the city. The purple flower in the bottom photograph looks to me like a kind of Delosperma, a genus of succulent species in the Aizoaceae family that produces a flower that novices might think looks like an Aster. Looking at the other plants in the wall I found that the majority of them were different types of Sedum. Sedums are also cold-hardy succulents, members of the Crassulaceae family. Sedums have become very popular in recent years due to their success and durability as green roof, and now green wall, plants. Because succulents use their leaves for storage of water and carbohydrates more so than their roots, they can often live and thrive growing in much shallower soil. With roots that only require a few inches of growing medium to properly anchor themselves and allow for water uptake, sedums can store enough water and carbohydrates above ground and can tolerate weeks of drought. People often think that regular rainfall is enough water for us to grow our favorite plants, but the reality is that many need supplemental water. Growers have been doing trials of Sedums for many years now and have proven that they have some of the best drought tolerance. As a bonus, many sedums have excellent fall color so I am very excited to see how this wall evolves through the seasons. One such grower who has become a real guru here in the States is a gentleman named Edmund Snodgrass who wrote a book entitled Green Roof Plants: A Resource and Planting Guide. This book and others on green roof and green wall technology are available to be viewed by the public free of charge here at our HSNY Library.

This green wall I think is beautiful and if you are ever in Williamsburg I suggest you go to N. 4th Street and check it out. There are companies nationally and internationally that sell the different modular components to construct green walls and I am constantly learning more about who they are and what they offer. As these green technologies begin to catch on more here in the United States The Horticultural Society of New York continues to be a knowledgeable and reliable resource for all. This fall there is going to be a full-day symposium on green wall construction here in the city and if you are a developer, landscape architect, landscape designer, or horticulturist, this might be a great opportunity to add this up-and-coming green technology to your repertoire. For more information, feel free to email me your questions any time.