Did The Flood Damage My Garden Soil? Flood Related Resource 2

(1)   GARDEN SOIL AND THE FLOODING:   The floods may have left some of you with concerns regarding the quality of your garden soil, especially if you are planning to grow edibles. Creating raised beds with new, good quality soil is certainly one answer. A raised bed is often a very simple way to provide an immediate, fantastic growing situation for plants without the work of amending our natural Colorado 'concrete' ...oops, I meant soil. However is it really necessary? We decided to ask Carol O'Meara, Extension Agent with Colorado State University Extension office in Longmont.

Are raised beds a better idea vs. attempting to amend contaminated soil for growing edibles?

Carol O'Meara:   Our community had flooding from rivers and storm water, both of which had the potential to carry pathogens (like bacteria, parasites) and pollutants (like hydrocarbons, fertilizers, heavy metals or mercury).  In most cases the water was of very high volume, diluting the contaminants, and moved rapidly in, then out, resulting in lower risk of deposition of these materials on landscapes.  Each property is unique in the potential for deposition, but in general, recovery of the soil for planting in spring can be accomplished.  Soil microbes and solar radiation are very effective in breaking down the pathogens and lighter hydrocarbons, so a healthy soil, plus time, is what’s needed to remedy many post-flood problems.  Incorporate high quality compost into the soil and allow it to stand for 120 days before replanting.  If you are concerned about pollutants such as heavy metals, you can have your soil tested for their presence by a soil testing lab.

Here is a link for soil testing. There are instructions for how and where to send a sample, a phone number to the lab, and a variety of soil test choices.



Beneficial fungi, bacteria, and other micro-organisms rebuild and improve soil.  Our recommendation is to consider adding compost, compost tea, or soil conditioners.  For your convenience we stock the following:

EKO Compost

EKO Clay Buster

Yard Care - Soil Pep

Earth Essentials - Sheep, Peat & Compost

Earth Essentials - Cow & Compost

Maxfield’s - Soil Conditioner

Soil Menders - Yum Yum Mix

Back to Earth – Rose & Bedding Mix


(2)   INCREASED WEEDS:   You may notice an increase in the numbers of weeds this spring.  We recommend an early application of a corn gluten meal pre-emergent.  It has to be applied early…before the weeds germinate.  We will keep it stocked in the Garden Center behind the main store.

(3)   POSSIBLE FUNGUS GROWTH?:   We were also wondering whether there would be a problem with increased mushroom or fungus growth for the 2014 growing season and if we should be concerned.  Carol's answer seems to indicate a wait and see approach since so much depends on the temperature and humidity of the weather during the growing season.
Carol O'Meara:   We had an increase in the mushrooms from decomposing organic matter when the soil moisture rose after the rain, and we’ve had a steady supply of moisture since.  But so much depends on the weather between now and spring that it’s impossible to predict an increase in fungi.  As we’re entering winter, fungi will not be very active; most are temperature dependent and have quieted with our cooler temperatures.

(4)   DISPOSING OF SOIL:   We hope that you don't have to resort to disposing soil, however if you do, then please contact Boulder County Hazardous Waste Management for guidance.

1901c 63rd St. Boulder, CO