Having harvested the last of the string beans (see September 25, 2013), we decided it was time to clear out the vines and start readying the west planter for winter.  Some gardeners would chop up the vines and till them into the soil to decompose and add organic matter (so-called green manure or green fertilizer).  Others might cut the stems off at the ground surface and leave the roots in place, hoping that symbiotic bacteria (if present) would continue to fix Nitrogen in the soil.

But neither of these ideas appeals to me.  Even though the planter is not that big (four feet by 12 feet), turning the soil would be a lot of work.  And anyway, we are following the no-till approach, which moderates decomposition, improves drainage and minimizes weed growth by leaving the soil surface undisturbed.  Somewhat ironically, it also maintains better aeration by eliminating compaction and encouraging the earthworm population.  In fact, our soil is essentially turned over several times a year by an abundance of energetic Lumbricidae.

Leaving the roots in place would require less effort—even less than pulling them out.  However, we do not necessarily have Nitrogen-fixing bacteria and it is not clear that they would have enough time to make a significant contribution to the properties of our soil.  Besides, it is more likely that we have too much Nitrogen rather than not enough (see June 22, 2013), as evidenced by our crops of carrots, beets and radishes which produced more leaves than roots.

Being completely honest, it probably wouldn’t matter if either alternative had a scientific justification because pulling the vines out is more in keeping with my nature.  I have been described as a neatnik and it is a characterization I do not deny.  At a certain level, getting the planter tidied up for its long winter nap is much more important to me than ensuring that the soil has a proper concentration of Nitrogen.  Our soil’s nutrient distribution can be adjusted in other ways and at other times but I have to look at the empty planter all winter long.