Monday, December 2, 2019

Adventures in Raised Board Beds


By Virginia Spoon

We found that raised board beds are easier to weed and keep people from walking over the irises. However, they have their problems. When we first started making the board beds the lumber was treated with chemicals that kept them from rotting, at least for 20 years or more. We weren't going to use the area for vegetable beds because of the danger of chemicals leaching into the soil.
 Some of our first raised beds--photo by Ginny Spoon

Our first board beds were started around 1996 with some lumber that was already used, given to us by a iris club member who was moving to a smaller home. We are still using those beds and the lumber has not rotted. Another friend  who was moving gave us some lumber that was never treated that he used for his vegetable garden.  He said it was a special wood that was very expensive and that was over 20 years ago. It has not rotted yet.

40 year old non-treated lumber--photo by Ginny Spoon

We made plenty of mistakes along the way. Don made many of the beds too wide, some were six feet wide and that made it hard to weed without walking into the beds. Some were too long, 30 feet (five, six foot joined boards). Many of the beds were too close together so that the mower would not go between the beds. I tried to tell Don that as the years went by we would be older and it would be hard to weed eat in between the rows. Unfortunately, that time has come to us.

Raised board beds, too long and too close together--photo by Ginny Spoon

Oh, what I would give to be able to mow with my riding mower in between the rows now. We have found that the ideal measurements for a board bed is four feet wide, eight feet long and either six or eight inches high. However, now the lumber is not treated with the same deadly chemicals and they barely last five years without rotting. The treated lumber even has a warning on it that says "Do not put in contact with soil." 

Rotted treated lumber that needs replacing--photo by Ginny Spoon

I recently purchased a cedar board kit that is four feet wide, eight feet long with two boards making it eight inches high. I used screws to put it together and used our two picnic tables to place it on to save my back. I then turned it over and put 1/4 inch mesh hardware cloth on the bottom to keep out the voles and moles that plagued that particular area of the garden. They must love the sandy soil there. I filled it with topsoil to the top. It is important to fill the beds to the top because if you do not it doesn't drain well and then you have a rot problem.

New cedar raised bed--photo by Ginny Spoon