The boards that form my raised beds are rotting away and I’m glad. I’ve been wanting to rearrange the beds so having to replace the boards gives me the opportunity and motivation to finally get this done.
One of the most frequent questions we get about setting up raised beds is what kind of lumber to use.
It’s natural to want to choose wood that will last the longest under the damp conditions of all that soil contact. Cedar is the best, then hemlock and then rough cut pine. Treated lumber would be an option for flower beds but not for vegetables; most gardeners avoid the treated products around their edible crops. For convenience sake and economy, two-inch pine boards, such as 2×8 or 2×10 work fine.
I have four raised beds that we set up about six years ago. I’ve been waiting for a good excuse to re-do them because I want to change the layout. They are set too close together to get the lawn mower between so I either need to weed-whack the grass around them or eliminate all the grass between them and use mulch to keep weeds from encroaching. And rather than four short beds oriented north to south, I’d like to set up two long beds, oriented east to west. It’s going to be a big job to change this over, so I needed those boards to rot down!
September is an ideal month to either re-make existing raised beds or set up new ones. The weather is cool, the summer crop is over, and the soil in the beds will have all winter to settle. Next spring the raised beds will warm up and dry out more quickly than the surrounding ground and I’ll be able to get my spring lettuce and spinach in the ground by the end of April without having to do any soil preparation.
The soil in my current raised beds is in good shape after years of compost and natural mulch amendments, so I don’t want to lose any of it. I’m going to start my project by first removing all the boards from around the beds and shoving the best soil into piles. I’ll then set up my new boards around these piles to save my having to carry the soil very far.
Since I don’t like having to reach across wide beds, my new beds will be four feet wide and twelve feet long, using two 6-foot long boards that will fit into my car.
I’ll smother any grass inside the new bed with six sheets of newspaper, and then rake the good soil I saved over the area to fill in the bed.
If the soil level is too low, I’ll add a mix of soil from my other open gardens along with some bags of composted manure, my own compost, some peat moss, some fallen leaves, some grass clippings (from lawns that have not been treated with weed killer); whatever materials I can gather that will break down over the winter. There are many types of bagged materials available at garden centers for those who don’t have a supply at home. In addition to composted manure look for various types of compost, peat moss and top soil in bags that are easy to handle.
It’s a good idea to use a variety of materials since each has its own qualities. I could even mix in some sawdust or fine wood chips to add some bulk to the mix. Grass clippings and manure will provide some nitrogen to help break down the materials.
Stir these different materials together with a spading fork or shovel. This mixture will settle so try to fill the new beds to the brim.
In future articles I’ll cover why I want to change the orientation of my beds and how I plan to use them. For now I encourage gardeners to consider putting in new or fixing up old raised beds this fall.
Photo courtesy EarthEasy.