Raised Bed Greenhouse

by Kerico in Outside > Backyard

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Raised Bed Greenhouse

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I built this raised bed greenhouse in order to have a place to grow vegetables that is safe from chickens, cats, squirrels, and caterpillars.

I enjoy the aesthetics of how the material change breaks up the scale of the structure and the friendly, orderly lines of the gable roof.

Materials List and Budget

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This is a rough budget for the project to get an idea of cost.

Ideally, I would have built it out of a naturally rot-resistant wood like poplar or redwood.

As far as tools it's pretty basic: circular saw, a staple gun, level, scissors, shovel, an impact driver, and drill.

Working Drawing

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This is the drawing that I used to build it, it is modeled in SketchUp.

Verify the smaller measurements as you go based on your unique site conditions.

The height of the raised bed is ergonomic and reduces the need to bend over to reach the plants.

It contains approximately 2.5 cubic yards or 67 cubic feet of material.

To reduce the amount of soil I needed to fill it with, the first layer is rotting logs that I had laying around my yard. On top of the logs is about a foot deep layer of native soil mixed with cow manure from the local garden shop. Google hugelkultur if you want to learn more about this method of using logs to retain moisture and fertilize your garden.

Raised Bed Greenhouse End

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First I prepped the site by clearing an area for the structure to go.

My yard was not level, so I used urbanite as a foundation. I placed pieces of urbanite beneath all four corners and the center and checked that they were level by placing a level on a board that spanned them.

I built all the side panels first, and then screwed them together in place on the foundation.

Next, I climbed inside and laid weed barrier down for the bottom, I stapled it in place halfway up the side walls.

Over the weed barrier, I lined the inside walls with a layer of plastic to separate the wood from the dirt.

Check that everything is square and level again and adjust as needed, since it will help your roof turn out nice and straight.

After filling it with logs and soil, I finished framing the roof.

Raised Bed Greenhouse Door Open

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Once the framing is complete, stretch plastic over all the sides without the doors. Staple it down with a staple about every 4". I left a bit of overhang on the plastic to deter bugs from entering and to shed some water away from the wood when it rains. I also added a horizontal brace every 4' to help keep the structure rigid and square.

The two doors are hung with three hinges each. I added 45-degree braces at each corner to keep them square. I'm not totally confident about how durable the door situation is, so I'm gentle opening and closing the top. It does make a satisfying sound when they fall into place.

I used flyscreen for the two end panels to provide ventilation and airflow to the greenhouse. There is room for improvement here because aphids are still able to get through and proliferate on my kale. I later added a secondary layer of flyscreen at a 45-degree angle, but I won't know if it is enough to keep the aphids out until next year since they have already infiltrated the greenhouse.

There is also an opportunity to have more control over growing conditions by installing a ventilation fan and a temperature gauge and the greenhouse could easily be outfitted with an automatic watering system.

​Plant Your Plants!

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Choose plants that have a short plant height at maturity and like lots of heat, sunshine and water retention.

I chose kale because it produces a lot and it is nice to have on hand when you only want a couple leaves to toss in your scrambled eggs for breakfast. The kale will quickly reach the top of the interior, so top it to keep the plants short.

I've also planted cabbage and romaine which is growing happily.

My long-term goal is to practice a no-till gardening method called KNF (Korean natural farming) to keep labor to a minimum. Also, to experiment with interplanting techniques to maximize the amount of food I can produce in this greenhouse.

It's been great having a dedicated place to grow delicate vegetables and reduce pests naturally.

It feels like having a living extension on my pantry!