It's all about the Dirt

Soil is the solution. For too many years we have been content to give just a passing thought to the soil in our gardens. Sure, many of us have a basic grasp of the concept of soil texture--- the proportional content of sand, clay and silt in a given soil ---but too often we just assume that because we’re in Colorado we are working with clay. We also assume that a simple, standardized formula for applying organic matter is the miracle cure for every site. Not so fast.

I believe that as we embrace the concept of regional landscaping, soil will prove to be the core focus around which all else revolves. Plant selection, water management and other resource allocations will all be more tightly tuned to work harmoniously with existing site conditions. Therefore, it’s time to ramp up our knowledge and understanding of soil.

Did you know that soil is classified and given very specific, identifying names just like plants? Names like Ascalon-Otero complex, Nunn sandy clay loam and Big Blue clay loam. Did you know that there are more than 20,000 different kinds of soils and that more are being discovered every day? (My brother-in-law, a soil scientist with the NRCS, is currently mapping Humboldt County California, an area notorious for its rugged redwood forests and marijuana plantations. That’s an adventure!) This chart* shows the correlation between plant classification and soil classification:

Plant Classification= Soil Classification

Phylum= Order

Class=Suborder

Subclass= Great Group

Order= Subgroup

Family= Family

Genus= Series

Species= Phase

*adapted from The Nature and Properties of Soils, 8^th edition, Nyle C. Brady

Once you identify the specific soil in your garden you can learn more about its characteristics. Only then can you make meaningful decisions about how to best manage it. Call the CSU Cooperative Extension in your county for information on their soil testing services and dig in!

You may also be interested in this upcoming event:

The third annual Sustainable Landscaping Symposium will take place at Denver Botanic Gardens on Thursday, March 4, 2010, hosted by the Front Range Sustainable Landscaping Coalition, Denver Botanic Gardens, and the Associated Landscape Contractors of Colorado (find them in the Links section of this page). This year’s theme is Down and Dirty: The Scoop on Soil.

The keynote speaker this year is David Montgomery. Mr. Montgomery is a Macarthur Genius Grant awardee, a geomorphologist, and the author of the acclaimed book Dirt: The Erosion of Civilizations. Don’t miss this rare opportunity to hear him speak in Denver – you will find him both thought-provoking and inspiring.

Other sessions will feature:

• Panayoti Kelaidis, Senior Curator and Director of Outreach at Denver Botanic Gardens, on how our soils have shaped life along the Front Range ;
• Kelly Grummons of Timberline Gardens on living soils;
• a panel discussion including Jim Borland , Mikl Brawner, and other horticulture and urban agriculture experts from our region
• extended breaks to give you the opportunity to meet and network with each other and visit with our sponsors.

For just 3 weeks, we are offering a special ‘stimulus rate’ – a full day registration for the discounted price of $75 ($10 off this year’s regular rate). This includes a continental breakfast and buffet lunch. The discounted rate is only available now through January 31, 2010.

Please visit www.botanicgardens.org and find this event in our online calendar, or call 720-865-3580 to take advantage of this discount. The registration fee will go up to $85 on February 1. Registration after March 1 will be $100.

Note: parts of this post were originally written for/published in Colorado Green magazine and have been reprinted with permission.