Soil in Raised Beds - Ask Extension
Four or 5 years ago, we built a couple of raised beds in our yard. They measure 3' wide by 18' long. We've added horse manure. We've added a pickup tr...
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Soil in Raised Beds #764682
Asked July 29, 2021, 5:00 PM EDT
Four or 5 years ago, we built a couple of raised beds in our yard. They measure 3' wide by 18' long. We've added horse manure. We've added a pickup truckload of a compost/manure/soil mixture. Still, the dirt level remains low. A landscaper friend said dirt wants to stay where it is born so not buy truckloads like that. Another friend suggested we put leaves on the beds in the fall. My question is: How can I have some dirt to plant in, (it seems to be all leaves)? Purchasing garden soil would cost a mint. Should I just plant seeds and seedlings in the leaf mast? Or put purchased garden soil around the plants and leave all the leaves in place? Thank you for any insights you can share.
Hennepin County Minnesota
Expert Response
Organic matter is an essential component of productive soil but organic matter volume and fertility are reduced by decomposition and cropping. That's why the depth of soil in the beds recedes. Adding organic matter to raised beds annually is the best way to maintain the depth and quality of the soil in them.
Leaves are a good source of organic matter but it's best to compost them before adding them to the beds. Shredding leaves before adding them is another way to speed their incorporation into the soil.
You can accomplish the same thing by adding compost, well rotted manure, peat moss, sawdust, etc. Some of these sources are relatively inexpensive but they aren't always easy to find and a truck or other conveyance may be needed to haul them.
The following publications may be of interest.
https://extension.illinois.edu/news-releases/refreshing-raised-bed-soil-generates-exceptional-results
https://www.canr.msu.edu/hrt/uploads/535/78622/Organic-Matters-figure-6pgs.pdf
Leaves are a good source of organic matter but it's best to compost them before adding them to the beds. Shredding leaves before adding them is another way to speed their incorporation into the soil.
You can accomplish the same thing by adding compost, well rotted manure, peat moss, sawdust, etc. Some of these sources are relatively inexpensive but they aren't always easy to find and a truck or other conveyance may be needed to haul them.
The following publications may be of interest.
https://extension.illinois.edu/news-releases/refreshing-raised-bed-soil-generates-exceptional-results
https://www.canr.msu.edu/hrt/uploads/535/78622/Organic-Matters-figure-6pgs.pdf
