Native Plants
Q. Who is Mr. Smarty Plants?
A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
rate this answer
Sunday - November 23, 2008
From: Houston, TX
Region: Southwest
Topic: Soils, Green Roofs
Title: Soil mixes for green roofs
Answered by: Nan Hampton
QUESTION:
We are trying to set up a green roof system on our own. What do you suggest for soil? It seems the soils are proprietary and unavailable to individuals.ANSWER:
Mark Simmons, Ecologist at the Lady Bird Wildflower Center, suggests the following recipe: 50% expanded clay, shale, or perlite; 30% decomposed granite; and 20% rice husks or another fine, slowly-degradable organic matter. There are other mixtures that also work. For the Seattle City Hall green roof the "Roof Garden Soil Mix was: "55% PermaTill 5/16" Expanded Slate or equal, 30% USGA Root Zone Sand, and 15% Approved Compost." Greenroofs.com suggests a mix of "1/3 clean topsoil, 1/3 compost, and 1/3 perlite or other inorganic material" for an economical option, but this has the potential for being heavier than some other mixes.
If you visit the Greenroofs.com directory page and choose the category "Suppliers>Individual Components>Growth Media", you will find a list of companies that sell soil mixes for green roofs. I checked one, ERTH Products, that advertised "ERTH-HydRock Lightweight Structural Soil" described as "an engineered soil designed to be lightweight for use on structural conditions such as roof top gardens." Another company, Permatill, offers "Green Roof Planting Media". There are more companies listed under the "Growth Media" category. Also, you can find more information about green roof soils by Googling "green roof soil".
More Soils Questions
Chlorotic Texas Mountain Laurel in Benson, Arizona
May 04, 2014 - I've planted a Texas Mountain Laurel in heavy clay soil in Arizona. It's been in place for 3 years and flowers each spring. However it's leaves are a shade of medium, yellowish green nothing like t...
view the full question and answer
Seeding Bluebonnets in Missouri
July 07, 2016 - I live in St. Louis, MO and obtained a packet of Bluebonnet seeds as well as a seedling. I read up on inoculating and scarifying the seeds, but I'm unsure as to the soil I should use. I was planning ...
view the full question and answer
Coffee grounds as mulch into vegetable beds
February 05, 2009 - Can you put too much coffee grounds as mulch into vegetable beds?
view the full question and answer
Adding Wildflowers to Corpus Christi
May 20, 2012 - I have a dry sandy yard, full sun in Corpus Christi with lot's of stickers mostly, want to transform to wildflowers. When should I plant, how should I prepare soil, should I dig out stickers? Which w...
view the full question and answer
Changing the pH of the soil
January 16, 2012 - Hi,
We have a job that has mostly Texas native plants on it. The architect is wanting to drop the pH levels of the soils to acidic levels that we don't feel is good for the plants and the area. ...
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |