Symphylan

Symphylan. Before this spring, I wouldn’t have associated that word with devastation. I might have even thought it something beautiful, like a symphony. No more. About a month ago, we discovered that we have symphylan living in several of our fields. It was an accidental discovery. The swiss chard was doing poorly, not growing at all. I wasn’t sure why. This was the field we had trouble with last year, but then I thought maybe it was because the pH was too high. This year, I knew the pH was right, so maybe we tilled the field too early and compacted the soil. I decided to transplant the chard to another field. I dug up the first plant and saw them. Even though I didn’t know much about symphylan, I knew it was what I saw: a tiny, white, centipede-like creature. I had heard a bit about them from other farmers, but never realized that this was the havoc that tiny creature could wreak.

These are the highlights of what I have learned about symphylan so far:

• They are arthropods, members of the class Symphyla (related to centipedes and millipedes)
• They eat plant roots and other organic material in the soil (eating the roots makes plants less able to take up water and nutrients, stunting their growth).
• They are most common in the western parts of Washington, Oregon and California.
• They do not move much horizontally, but do move up to three or more feet vertically through the soil.
• Organic farming practices (soil with good tilth, high organic matter, and low compaction) encourage symphylan population growth.
• They occur in “hotspots,” from a few square feet up to several acres in size.
• They are difficult to manage, because they migrate through the soil.
• The three main strategies to decrease populations are: tillage, pesticides and crop rotation. Pesticides are out for organic farming, which leaves tillage and crop rotation.
• Potato rotations have been able to reduce the populations enough that more susceptible crops can be grown for a year or two following potatoes.

OSU has been our main source of information, but we will continue our search. We are beginning to develop our management plan, but will get to the details after we exhaust all our information resources. We are considering what other options might be available to us, besides growing vegetables, in the infested soil.

Unfortunately, we have lost many of our spring crops (kale, chard, some cabbage and kohlrabi, fennel, artichokes, plantings of peas, beets, spinach, some lettuce and onions). Once I realized what was happening, I stopped planting in the affected fields (pretty much all of our half-acre spring field and a good quarter acre of one of our summer fields along with patches in the other summer field) and have been scrambling to plant left over starts in other places and restart some crops. Fortunately, we have areas that are unaffected and crops are growing nicely in those areas. The beets and carrots are beautiful this year. Summer crops are on their way.

While we are very discouraged by this discovery, we know that many organic farmers face the same problem and manage it successfully (mostly!). We are encouraged by their success and will do our best to manage it, too. This is not the end of this season, it has just put a damper on the beginning. Summer and fall crops are still to come and we are looking forward to lots of good things to eat.