The Guild Report:   
Landscapes Over Rooftops and Structures         

November 2014  
In This Issue
Point of View
Certified Green Roof Installers
Landscapes on Structures
Maintaining Landscapes on Structures
Dry Farming
Quick Links

Point of View 
Employee Owner

Cristina Orozco

Our family moved to the bay area from Las Vegas when I was hired by Gardeners' Guild,, September 1st.   


The weather here is a welcome change from the hot climate of Las Vegas.  


Love the company and its culture and values.  Everyone has been helpful and supportive.  My job is HR - that means I'm always looking for good people.  It's sort of an extension of sales.  I also do payroll and benefits and am available when employees have questions. 



Cristina is our new Human Resources Manager.  In a short time she is become a vital part of our family. 

Gardeners' Guild is a
Certified Green Roof

As part of our green roof installation, Gardeners' Guild was certified.

This certification applies for both maintenance and installation.    


It includes installation of plants, soil, drainage and irrigation.   

Gardeners' Guild Our Planet
See the video on our sustainable program!


As Thanksgiving is upon us and we surrender to this prelude to the holidays, I happened on a message that is good to remember.  I hope you enjoy it.

We may not know for sure if El Niņo will visit this winter, but the rain this week was awesome!  It was heavy, there was lightening, even hail was reported.  Last I heard, yet another system was headed our way for tomorrow.

And, because you are likely still concerned about water you may find the results of the California State Water Resources Board's survey of water use interesting.

The survey results yielded a few major points -

Lower-income and densely populated neighborhoods use much less water than higher income single family communities.

Where tiered pricing has been used, it hasn't necessarily been successful  because wealthier customers can afford to pay the higher bills.

Most cities saw their per capita use decrease since last June, there are wide variations in water usage by city.  It ranges from 50 to 500 gallons per day. 

Though the report seemed to raise more questions than it answered, it will help lay the groundwork for future state policies.

Have a wonderful Thanksgiving.

All the best,
Gardeners' Guild Inc.
Types of Landscaping on Structures    
Some of the most beautiful (and complex) landscapes in our urban centers are on top of buildings or garages.  

You might notice that some of these landscapes, called living roofs are just plant material, others have hardscape and pedestrian traffic. 

The differences between these landscapes represent the two kinds of green roofs. 

An external green roof (see photo on the right) is simpler than its counterpart, an internal green roof.  Not suited for foot traffic, they are shallow - their growing medium is from two to six inches.  Low care plant material like succulents are ideal for this kind of roof.  Watering requirements should be low, as well.  There is an increasing number of modular products making its installation simpler.

This type of roof is well suited for residences and it's also wildly popular in San Francisco. Why not? It is good for the environment and a wonderful sight to behold.
An internal green roof is more complex.  (see photo on right) Because its height can be several feet tall, they accommodate foot traffic, a variety of plant material including trees, hardscape, furniture and water features. 

Many of the commercial properties in the city have constructed these types of landscapes on top of parking structures.  They are also above ground courtyard spaces or on rooftops or balconies.   
For the rest of this article we will will talk about these types of landscapes and refer to them as on structure landscapes. 
Maintaining On Structure Landscapes    
Their multiple layers, weight, and irrigation are reasons they require rigorous monitoring.  There are three important factors to monitor.

Water needs to be able to flow unimpeded through soil to drain outlets.  These drains can easily get clogged.  And, it would not be noticeable until a tree dies or flooding occurs.  One of our Account Managers  says - "a lot of my accounts are over structure landscapes or rooftop patios and drainage can be a problem.  We have found that a sustainable approach (no chemicals/organic products) can help with older sandy planter bed soil.  And, we still need to constantly check that planter beds are healthy all the way down to the drain."  Whatever the method, drains need to be closely monitored.

Waterproofing As this type of landscape ages the waterproofing liners eventually wears out. It is common to have a planter renovated due to water leakage as a result of drainage failure.   Close monitoring by a knowledgeable professional is critical here. 


The soil needs are different from those of a typical in-ground landscape.  As opposed to needing a high percentage of organic matter, a landscape on top of a structure depends on soil with a high mineral content so it doesn't break down.  These soil mixtures need to be customized and blended for best results.     


As with any landscape, plants need to be detailed and pruned for their health and pedestrian safety. And, landscapes over a parking garage or roof should be maintained by a contractor with expertise handling its additional requirements.   


Gardeners' Guild specializes in installation, renovation and maintenance of both intensive as well as extensive living roofs.  Do call us with any questions. 


"Dry" Farming?          
With the potential of ongoing drought conditions looming, it begs the question of how to grow produce with less water.  This KQED story on the results of a study on the effects on produce grown without irrigation caught my attention for that reason. 
On experimental farmland on the US Department of Agriculture's campus near Fresno, a plot of pomegranate trees were watered with a solution of salt, boron and selenium.  They also experimented with 35% of normal water and 50% to determine if the drought impacted their nutritional value. 

The fruit trees with less water grew much smaller and bore tiny fruit.  When tested, their findings showed no difference in fruit quality and the tiny pomegranates seemed to have double the antioxidant content of pomegranates grown under normal conditions.  The pomegranates grown with salt and boron also seemed to have double the antioxidant content as those grown under ideal conditions.  It looks like stressed plants produce more antioxidants.

For more information see KQED blog.