Advice about symphylans - Ask Extension
Greetings! I realized I have symphylans in my home vegetable garden. I had noticed symptoms for a couple of growing seasons until I finally got the ma...
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Advice about symphylans #938782
Asked July 10, 2026, 1:35 AM EDT
Greetings! I realized I have symphylans in my home vegetable garden. I had noticed symptoms for a couple of growing seasons until I finally got the magnifying glass and saw them when I scooped with my trowel. I Read about them in the Steve Solomon book and so I attempted to start the going fallow process two years ago but I realize that I may not actually have been letting them be truly fallow because in one of my beds I allowed volunteer calendula, borage and poppies to grow and in all the other beds I covered with straw that grew into grass which I eventually cut down and removed early this summer. So my questions are:
1)Do I have to start the fallow process all over again and go a full three years?
2)What process do you recommend for letting them go fallow? Just bare soil? Covering with woodchip? Black covering?
3) Does planting potatoes really help and if so, any particular type and can I plant crops the following season or later in the same season like garlic?
Any tips or guidance is appreciated and thank you for this service and for your time!
Warm regards,
Heidi
Multnomah County Oregon
Expert Response
Hi Heidi,
Thank you for using Ask Extension.
I looked this up in the PNW Insect Management Handbook and found this article
Biology and control of the garden symphylan | Pacific Northwest Pest Management Handbooks
My first question is "What are your goals?" Based on the article, tilling is recommended but it's unlikely you can eradicate symphylans, only manage the population. Further, most of the research and recommendations are based on commercial-scale agriculture, not the home gardener.
Unless you have a serious infestation, most crops can handle some damage and that transplants fare better than direct-sown by seed.
I'm not sure if the volunteer plantings really affect the idea of fallow because even on a commercial scale something grows because of the seed bed that exists in all soils.
If you used straw and not hay, you may have had wheat or oats grow as the grass to which you refer, that is pretty easy to pull up.
It appears that potato is quite effective in reducing the population, but you could try a combination of strategies like putting down black plastic to warm the soil for 4-6 weeks. That may have the symphylans rise to the surface and then remove the plastic and till the soil. You probably have time to cycle through that twice and still be able to plant your garlic in the fall.
Thank you for using Ask Extension.
I looked this up in the PNW Insect Management Handbook and found this article
Biology and control of the garden symphylan | Pacific Northwest Pest Management Handbooks
My first question is "What are your goals?" Based on the article, tilling is recommended but it's unlikely you can eradicate symphylans, only manage the population. Further, most of the research and recommendations are based on commercial-scale agriculture, not the home gardener.
Unless you have a serious infestation, most crops can handle some damage and that transplants fare better than direct-sown by seed.
I'm not sure if the volunteer plantings really affect the idea of fallow because even on a commercial scale something grows because of the seed bed that exists in all soils.
If you used straw and not hay, you may have had wheat or oats grow as the grass to which you refer, that is pretty easy to pull up.
It appears that potato is quite effective in reducing the population, but you could try a combination of strategies like putting down black plastic to warm the soil for 4-6 weeks. That may have the symphylans rise to the surface and then remove the plastic and till the soil. You probably have time to cycle through that twice and still be able to plant your garlic in the fall.
