How To Choose Lumber For Garden Bed Construction

Posted on: 3 March 2021

Raised garden beds can be used to grow vegetables or flowers. When constructing the beds, it's important to choose the right lumber for the job.

What Are You Growing?

One of the first decisions to make is the type of wood, and this depends heavily on what you plan to grow in the raised bed. Any wood chosen must be resistant to rot and insect damage, which narrows your options down to cedar, redwood, or pressure-treated lumber. Other types of wood can rot quickly, sometimes in as little as a year in wet climates.

If you plan to grow edible plants, such as herbs or a vegetable garden, the best option is untreated cedar or redwood. These woods are naturally rot- and pest-resistant, but they don't contain any harmful chemicals that could leach into the soil and then into the food plants. For ornamentals and flowers, pressure-treated lumber is the best and often the least expensive option.

How Much Maintenance Is Acceptable?

Wood garden beds may require some maintenance. The least amount of maintenance is needed for pressure-treated wood or railway ties since these can last decades without any help. There is no need to paint or finish them in any form.

Cedar and redwood don't need to be sealed or painted, but they will slowly decompose over the years. This occurs much slower than it would with pine or another quicker rotting wood, but it isn't unavoidable. You can decrease the need for maintenance and replacement of cedar and redwood by installing them on top of a gravel trench or a base of pavers. This prevents ground contact and slows down moisture damage.

Do You Want Decorative Elements?

Some garden beds are completely utilitarian, which means all you need is some lumber in the right width and length to create the box size desired. In this case, 2-by-6 inch boards can be used to create the box, adding additional boards until the box is the desired height.

For decorative beds, such as flower gardens, you may want to affix wooden lattices along one side of the box. This provides both an attractive background as well as a trellis for vines and climbing plants. You may also want to look into more decorative lumber options. For example, pressure-treated railway ties provide rustic charm for a country home, or wooden scalloped shingles can be used to create a decorative edge along the top of a wooden garden box set in front of a cottage.

Contact a lumberyard for more help when it comes to choosing the perfect wood for your raised garden bed project.