Where can I send soil or worm castings for testing for N-P-K levels?

Asked February 3, 2018, 5:13 PM EST

I would like to try straw bale gardening and for the last year have been actively into vermiculture and have worm castings that I would like to have tested to determine their N-P-K levels for both conditioning my straw bales and for making potting soil.
Any help or advice on any of the above would be greatly appreciated!
Thank you!

Weld County Colorado soil testing vermiculture soil testing laboratories making potting soil

1 Response

Vermiculture is a fascinating topic. Here is research-based information for you from Colorado State University (CSU): http://planttalk.colostate.edu/topics/soils-amendments-composting/1622-composting-worm-composting/

You are right! Testing soil before planting is always a good idea. Here is a link to the homepage for Colorado State University’s soil test lab - http://www.soiltestinglab.colostate.edu/.

How can you can most accurately sample your soil? Check out: http://planttalk.colostate.edu/topics/soils-amendments-composting/1606-soil-tests/

Here is more information for you about straw bale gardening: http://msue.anr.msu.edu/news/no_digging_required_straw_bale_gardening

You also asked about making potting soil. Research suggests: Do not use native soil, even if you can pasteurize it. Most native soils have a high percentage of clay particles that easily compact reducing the oxygen that is available to the roots. (Source document: http://extension.colostate.edu/topic-areas/yard-garden/container-gardens-7-238/ )

If you want to see straw bale gardening testing in action, you may want to visit Treasure Island Demonstration Garden in Weld County, Windsor, CO.

Have fun trying straw bale gardening!