Whether gardening year-round in a greenhouse, or starting up an outdoor garden this spring, here’s a quick round-up of several ways to make your own raised garden beds.
Easily stackable, these can be combined in any configuration. Blocks should be secured together using mortar or rebar. We suggest also filling the pockets with stone or gravel. You can add a top layer of soil in the openings, which make perfect planters (the roots helping to secure the blocks together too).
Note! Cinder blocks can make your soil more alkaline (a higher pH). If planting in the cinder blocks or directly around them, choose a crop that can tolerate alkalinity like chard or spinach. You can also adjust the pH of your soil with amendments if it gets to be a problem.
The most common type of outdoor bed, cedar also works well in greenhouses. We often design cedar beds in a U-shape layout to maximize space in our year-round greenhouses. Indoor or outdoor, you can build these by installing 4″ x 4″ posts in the ground and securing cedar boards to the posts. To increase longevity we often recommend lining the inside of the bed with a layer of pond liner, vertical drain, or other protective barrier so the wood is not continually exposed to moist soil.
You can use corrugated steel as a siding material around wood posts, similar to the cedar beds shown above (a simple pinterest search will yield lots of examples of this). Or, metal animal feeders make excellent easy raised beds. These aren’t exactly made by you, but would need to be picked up at a hardware store or farm equipment store (i.e. Murdoch’s). You can also make these beds into self-watering planters with resovoirs on the bottom. Make sure they have a drain so water can exit.