Soil to grow vegetables
Hello, I greatly appreciate this service you offer, I live just east of Bandon on 8.5 acres, most of it wooded. I have a greenhouse with raised beds and now it has 100% G & B Raised Bed and Potting Mix in them, but now I wonder if that's good enough. The mix has settled and I need to bring the level up; the soil on my property is poor, either sandy or clay. It lacks that nice deep dark color of good soil and it is poor at growing things. I'm thinking of adding some of that soil to my raised beds along with some compost I bought from a local supplier who used steer manure, fish products and forest duff and lets it cook for 1 year. I wonder if I still need some soil regardless of how poor it is for any needed nutrients or 'stuff'. What do you think of adding soil, even if it's poor, along with the compost to my greenhouse raised beds? Thank you,
Thanks for your question. The following OSU Extension article recommends against adding native soil to your raised bed gardens (page 5): https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/fs270_1.pdf
You can purchase topsoil to add that doesn't have insects and pathogens present in native soil, and add well-aged organic material, or compost. Be careful about manures, because they often have mineral salts or pathogens, if not cured for 6 months or so, which can be harmful. The finer the medium, the better. You don't have to let it 'cook' for a year if it has already been aged by the producer. But if it has not, aging is certainly something you can do. Just make sure it has plenty of air circulation (to prevent fungal growth), water with good drainage, and heat.
Hope this is helpful. Good luck!
Thank you for your response, however you said: The following OSU Extension article recommends against adding native soil to your raised bed gardens (page 5) I read page 5 multiple times and no where do I see it recommending AGAINST adding native soil.
You said I could buy topsoil that that will likely have insects and unknown pathogens.
So, to be clear, you are saying it is a bad idea to add native soil to my raised beds, correct?
Thank you for your thoughtful reply, Jim. I apologize for being unclear. The text I was referring to did not say outright “don’t do it.” Rather, it recommended what to do. As this article indicated, not including native soil (in an area whose native soil consists largely of clay) keeps the raised beds’ growing medium light and able to allow water to drain, while keeping the ability to hold nutrients for plants’ use. Here is another resource: https://extension.wsu.edu/clark/2016/03/raised-bed-gardening-good-choice-with-northwest-soils/ The topsoil and compost available commercially—especially from organic resources—are less likely to have pathogens and, at least as importantly, pesticides. We have heard of some sources of compost that even include walnut bark, which contains a (natural) chemical that retards growth of many plants. To sum up: don’t add native soil, research your topsoil and compost sources, and you should have the best vegetable garden around!