New Home built in Jacksonville Oregon
Hello, I am from the East coast and have garden for many years. We recently built and we are left with compacted clay soil. I would like to start a vegetable and flower gardens. I cannot even put a shovel in the ground it is so hard. I had to use a crow bar and hammer to get soil samples for analysis. I have attached a picture of the soil analysis for your review. My idea in order to create microbial life in the soil is to rough up the surface (how?) and plant a cover crop. Afterwards, I would cover the areas with wood chips/leaf clippings. What would you recommend I use as a cover crop and do you agree with my procedure for soil building. Thank you in advance, Anthony Gaudioso
Jackson County Oregon
- My recommendation, and my own practice has been to build raised beds and fill them with compost and other organic matter, and not try to garden in the native soil at all. Over time, the clay will be mixed in with the compost. You have to top up these raised beds over time.
- You'll also want to check for bedding mix pH and phosphorus over time as well. But it's easy to succeed in the first year of a new garden, so no need to run a soil test.
- If you purchase compost, ask the seller about laboratory analyses that may have been run; this should be available to you.
- If you add manure to the beds, be sure to get something that was kept covered. Weed seed blow into manure and germinate once you start watering.
I'm interested to know whether you see cracks forming in the surface of the soil.
Soil test recommendations:
- I'm surprised at their phosphate recommendation. The soil already has a high Bray test result. I think for a lawn or vegetable garden, you could reasonably skip the phosphate for this year. When I saw the phosphorus level in the soil, I assumed it had been manured over a long time, but low organic matter and sodium suggest it has not been manured.
- If you do lime, apply only agricultural lime, and do not apply dolomitic lime. Your soil already has more than plenty of magnesium.
- Although 6.5 would be a respectable pH for a vegetable garden West of the Cascades, the soil has high iron and moderately high copper. Increasing the soil pH closer to 7 will force more of the metals into insoluble molecules. Metals can negatively impact plant roots.
- Once the summer growing season has ended, and as the autumn rains begin DO NOT apply nitrogen - whether as a fertilizer out of a bag or as manures. Nitrogen is highly soluble in water, and will run off your site, with potential water quality threats to nearby streams, or will leach below the level of plant roots and threaten groundwater.
- If you do plant cabbage family vegetables, they will benefit from the addition of boron. I recommend a product like 20 Mule Team Borax or similar as a boron source. I apply 1/2 teaspoon per 12' x 3' raised garden bed. It's easiest if you mix the boron source into sand, and apply by salt shaker to the bed. That sounds like a ridiculously low dose, but in the case of micro-nutrients, the dose makes the poison. The difference between not enough a too much is very fine.
- As for zinc, I suspect it's not so important for a winter vegetable garden. If you were growing sweet corn for your livelihood, it might be a different thing, but I've never applied zinc to my soil, the level is very slow to change. Save it for the moss that will grow on your roof.
- In my raised garden beds, I have allowed vetch to become a self-seeding perennial.And mache or corn salad is a freely self-seeding winter cover crop. It's also edible as a salad green.
- In the summer I grow buckwheat in areas left bare by broad-scale weed removal (I let horseradish get out of hand ...)
- By about mid-October I will replace the buckwheat with crimson clover. It will develop over the winter and bloom in the spring.
- I don't like the grasses and cereals as cover crops, although they are frequently recommended for production agriculture. They're just too hard to till into the soil. With a tractor it's different.
Yes I do see cracks forming in the surface of the soil.
Thank you for the informative answer to my question.