Wednesday, November 9, 2011

Nature Irrigated Green Roofs - how much water do you need!

Nature is amazing.  It has not rained for several days here and though we did recently have a little rain we are still far below our normal.  In fact Jacksonville is still classified as officially experiencing severe drought conditions.

National Weather Service Drought Index
Yet nature provides ample water, even in times of drought here in the form of water vapor.  Good green roof design takes advantage of all sources of water, including morning dew.

Nature's irrigation - morning water vapor

I am constantly amazed at just how much water rests on the green roof plants some mornings.

As though an irrigation sprinkler has been turned on across the roof, opportunities exist for the plant designer to use those species capable of condensing (those with fine leaves, hairs or waxy surfaces) to capture the water then direct the droplets to the green roof planting media below.

Working with an international hotel chain to improve their landscape vegetation I was asked to diagnose why a large collection of very big planters were doing so poorly.  A large roof overhang directly above prevented morning water vapor from reaching the plants.  However, only a few feet over and out from under the overhang other planters looked lush.

Fog and morning dew can contribute an important source of nature supplied irrigation.

I make it a regular habit to walk green roofs early, middle of the day and late.  Surprises abound always.  This morning I was amazed at just how much water was on the plants.  Who needs a sprinkler?


Santo Caridine said...

Mother Nature does not neglect her children. Especially plants, who get their nurturing directly from Her. The plants in a green roof are given a daily supplement of dew and, as long as the soil is healthy and fertile, the plants would stay as green as they are.

Emma Phillips said...

“Good green roof design takes advantage of all sources of water, including morning dew.” – I totally agree. That’s why, if you ever want to build a green roof, you must plan it carefully, and make sure you can take care of it, especially during the dry seasons.

Noreen Saint said...

I have to agree with you, Emma. There are some things that you need to consider first before you build a green roof. Not all types of green roof are suitable for your roofing structure, so you must examine first what kind of green roofing system will most likely go well with your roof. By choosing the right kind of green roof for you, this will also help you determine the kind of maintenance you need to do to make sure that it will going to succeed, and thrive, in the long run.

Penelope Dingee said...

That’s a simple and neat roofing you have. I'm pretty sure that the guys who installed it worked really hard, because it’s apparent that they did an excellent job. I hope your gutter is up and ready now, so you can focus on other more important things.

Ronald Miller said...

Planting on the roof is a way to go green and to be thrifty. In that case, not only do you help save the environment, it would also provide you with something to eat, organically, helping you to save money as you don't have to buy your vegetables since you already have it right up there on your roof. You don't also have to maintain it that often, as nature will provide you with enough nutrients that the plants need to survive and grow.