This week I would like to talk about raised beds. There are many different ways to make raised beds. So I’ll go through different types of materials that you can use and some basic principles to use when building your raised beds. I’ll also talk about situations where I like raised beds over growing in the soil and vice versa.
Raised beds are a great tool to use if you have don’t have a lot of sunlight in your yard. Plants grown in raised beds will still need full sun, but if you only have a small area of your yard that has full sun, a raised bed is a good way to maximize that. If you have slopes that are too steep to plant, leveling out a small area and putting in a raised bed in that spot is another good idea. Oftentimes, the best soil in Towns and Union is found in river bottoms. If you don’t the good fortune of putting your garden in one of those places, growing in raised bed will also be much easier than fighting with heavy clay soils. Raised beds are also going to have fewer weed issues, and less soil compaction. You can build elevated raised beds to that you don’t need to do as much bending down.
Dimensions for a raised bed depend on the materials that you are using. Generally, I like raised beds that aren’t more than 4 feet across. If you have really long arms you can make them wider. I also like beds that are about 8 feet long. If you make long beds, it’s just more difficult to walk around them, especially if you’ve put a bunch of raised beds next to each other. 10 inches height will be enough depth for most vegetables. Potatoes will need more depth. The deeper you make the raised bed the more material you will need to fill it. Soil to fill raised beds costs money, so don’t make them needlessly deep. If you have tall crops planted in your raised beds they can shade out other crops, so orient them in a north-south direction. You want to the raised bed to be completely level. To do this you may need to dig out the place where you’re putting it.
Let’s move on to materials that you can use. There are several different types of lumber. Cedar is very good, because it does not rot quickly. However, it is very expensive. Cypress is often easier to get than cedar. Oak and other hardwoods can be difficult to find in sufficient quantities, and are only a little more rot resistant that pine. Pine is the most readily available and cheapest lumber. It will rot, but I’ve seen where you can get several years of use out of pine. An alternative to lumber is cement blocks, brick, concrete, or stone. If you are going to build the wall high, you would need some mortar to keep the walls from falling.
The research that is available says that pressure treated wood is safe to use for food production. Arsenic is no longer used to pressure treat wood, and has not been used since 2005. Wood treated with creosote should not be used. Railroad ties and utility poles are treated with creosote.
If you have questions about building your own raised beds contact your County Extension Office or email me at Jacob.Williams@uga.edu.