Raised Bed Recap

Yesterday we had a great workshop presented by the people at the WARM Training Center and Reclaim Detroit. They came out and discussed their work recycling wood from local buildings for raised bed kits, planters, bird houses and benches, all of which we now have for sale at the store. Participants got a chance to help build two raised beds that are now sitting in front of the store, waiting to be planted with beets, radishes, carrots and other crops for late summer and early fall. Below is some information on raised beds. If you get a chance, check out the great work being done by Reclaim Detroit at reclaimingdetroit.org.

The Benefits of Raised Bed Gardening

Raised planting beds offer the gardener many advantages from improved aesthetics to better control of soil conditions. Gardeners here in Detroit struggle with heavy, clay soil and fill dirt that is hard to work. Constructing a raised bed, and filling it with a fluffy mix of topsoil and compost, is an easy way to bypass this problem. It’s also a way to work around lead contamination in the soil, although in this case, the bottom of the raised bed should be sealed off from the ground level soil.
Raised beds are quicker to warm up in the spring and are more likely to be dry enough for planting early in the season. The raised surface prevents the soil compaction caused by walking next to garden beds. This means that more air gets to plant roots, increasing the yield.
Some people prefer the orderly look of a raised bed, especially in urban and suburban areas where a lot of people are likely to be looking at your garden. And many people find it easier to work an elevated surface than having to reach all the way to the ground. For these reasons, many community gardens use raised beds to preserve an attractive appearance and make the spaces more inviting for differently abled people.

Siting and Building a Raised Bed

It’s best to construct a raised bed on a relatively dry and level site. To improve drainage and protect the bottom of the bed, the gardener may want to put a thin layer of stone or gravel under where the bed is going to be. Wood sealants and preservatives aren’t generally used in organic gardening because these have the potential to leach into the soil. But an application of linseed oil is acceptable and can help protect the wood.
For people with weed issues, a layer of landscape fabric at the bottom of the bed will keep weeds out. A layer of cardboard will also last long enough to suppress most weeds. It would then break down in about a year and allow roots from the plants in the bed to penetrate the ground level soil.
Detroit Farm and Garden recommends filling the raised beds with a mix of half compost and half topsoil. The topsoil mostly provides structure along with some nutrients and an ability to hold water. The compost provides nutrients and spaces for air and water in the soil structure.

Caring for Your Raised Beds

Overall, caring for plants in a raised bed should be easier than taking care of plants in other spaces. These beds are usually filled with a neutral soil mixture that benefits most vegetables. And the un-compacted, easily drained soil is a good growing medium. But, this drainage means that these beds are quicker to dry out than the surrounding soil, so they may need a bit more water during dry periods. Gardeners can try using straw mulch to preserve moisture and cut down on the need for extra watering.