Best Soil Recommendations for Raised Garden Beds
One of the benefits of raised garden bed gardening is drainage, but this feature also makes slightly different soil requirements for your garden box. You can fill your beds with your own yard topsoil, but it's a good idea if you want your plants to have the best chance of keeping weeds out. Both options are discussed below.

The Best Homemade Soil Mixes:

50% of the screened topsoil is made from healthy loam.

50% screened compost, which can be your own compost, mushroom manure, animal manure or fish compost.

Best Quality Soil Mixture:

1/3 peat moss

1/3 Vermiculite

1/3 compost mix similar to above

The last combo above will help get rid of weeds, but the real key to these combos is composting. No matter how good your topsoil is, without compost your beds will fail and need to be re-added every year.

Sustained soil construction can be accomplished in a number of ways:

Layer method: Fill the bottom of the garden box with a layer of leaves, grass clippings, straw, sawdust, and other organic materials, and top with a layer of cardboard. Next, add soil. Over time, this mixture breaks down into a rich compost.

By growing green manure: For every two crops, grow one type of legume, such as clover or peas, in raised beds. When ripe, chop them up and dig them lightly into the soil. Leave it to rot for the next season.

Add more compost: Add any combination of organic compost for a light, crumbly, fluffy texture.