Tuesday, February 3, 2015

Is My Container Safe?

I was having a conversation with a visitor in the garden this past weekend on the safety of growing vegetables in non-toxic conditions.  We chatted on and on about the materials appropriate for raised beds and eventually got on the subject of what types of containers are safe as well.

If you're anything like me, I'm always rummaging through the house or garage looking for the perfect pot to grow some veggies in.  There just never seems to be enough room to grow everything the family likes. Utilizing containers provides an excellent means to get some extra space until we're able to build more beds on the property (or I should say, until I'm able to convince Rick to build some more beds).

Most all vegetables will grow rather well in containers if you choose the right size pot for the veggie at hand.  Each year, in addition to our raised beds, Rick and I grow about 50 tomatoes and the majority of them are in pots.  About the only drawbacks are the additional watering since they tend to dry out faster and the potential for some containers to leach harmful chemicals into the soil.  This makes it imperative to do a little homework before planting. 
My driveway garden in the EarthBox containers!
http://earthbox.com/

My favorite container is the EarthBox, pictured to the right, which came my way as a gift many years ago.  These are about the best HDPE option that I have found which produce on par with plants out in the raised beds.  In addition, they are UV stabilized, food grade safe, made in the USA, and of very high quality.  

Each year, I try to add a couple more to the driveway garden and many of the containers still look great a decade later.  Another great aspect of the EarthBox is a company that continues to offer support, for any replaceable parts needed, so you're never out the investment placed in the box.  While these are available locally at Pikes, I always seem to find much better deals straight from the website.  Often, you'll even find a good sale around different holidays as well as coupons for free shipping.  

When it comes to the backyard garden, I tend to use any pot that is recommended as safe from leaching, or whichever ones give me the greatest level of comfort from leaching.  Natural materials, i.e. concrete, cedar, redwood, and such, are always best, but there are many options for plastics as well. Big box retailers carry food safe five-gallon buckets and many pots have symbols known to be acceptable.  For utmost safety, it is wise to avoid containers with the symbols 3, 6, and 7.  These particular plastics are known to have the highest level of risk for leaching chemicals into the soil, especially when they're exposed to elevated temperatures from full sun exposure over prolonged periods.

I wasn't able to find any studies showing the rate that plants absorb harmful toxins when grown in plastic containers as well as to how toxic these levels are to us as we consume the food from them.  I have found a few scientists blogging back and forth determining that there is a need to have this type of research performed.  In fact, they say there is an outcry from organic gardeners for it.  Some science suggests that the amount of organic matter in the soil plays a part in how much toxic material the plants in containers can absorb.  However, until there is some definitive research, it is always better to error on the side of caution and use containers that fit into your comfort level for safety.

LIVESTRONG.com has some guidelines as to which plastics tend to be the safest for growing edibles and a link is below for your convenience.    

http://www.livestrong.com/article/183959-which-plastics-are-safe-to-use-as-containers-to-grow-food/

The University of Florida Extension Service also has some excellent information for the appropriate size containers to choose when growing different vegetables.  If you scroll down to page 41, there are also some safe container guidelines.

http://sarasota.ifas.ufl.edu/AG/OrganicVegetableGardening_Containier.pdf - link to the University of Florida IFAS Extension Service. 

Happy Gardening,

Denise, Beds 25 & 29