- Access to plants is more comfortable compared to ground-level (less bending down) which assists planting, inspection and harvest.
- Drainage is improved, helping to avoid root rot, fungus etc.
- It looks way cooler than a hole in the ground.
- Invasion from lawn grass is eliminated.
- Infestation by insects is reduced and can be more easily controlled.
According to various people who own them and confirmed by a few books and internet articles I've read, a raised bed offers a number of advantages over simply digging a hole and planting vegetables:
There were a number of reasons why I decided to design and build one myself (as many people do, it's trivial).
- Material control: Cedar is natural, looks fairly decent, lasts well outside and requires no chemical treatment that could get into my vegetables.
- Dimensional control: I get to decide the exact size and shape.
- Depth control: Due to uneven ground at the site, I needed the ability to build a tapering planter that left-to-right is about 12" on one side, 20" on the other, and had a similar but less pronounced taper front-to-back.
- I wanted something that looked better and more interesting than local stores could provide.
- I wanted a feature (the climber-support posts and oriental headboard) that wasn't available on store-bought solutions.
- It would be fun to make.
The 'headboard' and its posts provide anchor points for 50lb fishing line to be strung across in a grid, much like a soccer net that in turn gives climbing plants needed support. It isn't expensive and doesn't rot or stretch over time (at least, not within the time frame of a growing season), and it's almost invisible. Some details I should point out:
- Each plank across the front and back is approximately 6" x 8ft. Overall area is 4ft x 8ft and about the largest feasible assuming you want to walk around it to harvest and not wade through it.
- Where possible all fixings (premium weatherproof deck screws) were driven from the inside out, so you don't see them.
- The corner posts are structural, preventing each side from parting with its neighbors and preventing each row of planks from moving apart from the one above or below it.
- The center posts are mainly decorative but still serve to prevent the plank rows from separating.
- The second corner post in each pair is for looks rather than structurally necessary; one would have sufficed.
- Corner and center post height differences were chosen that way on purpose, for looks alone. However, protruding corner posts generally were a desired feature because it provides some protection from a hose being dragged across the planting surface and gives raised anchor points for netting (which it turns out we didn't need).
- Neither posts nor planks enter the ground, they sit above it.
- 3 ft rebar was used to prevent the back side from bulging. I was prepared to use some on the front too, but found it unnecessary.
- The top row of planks is capped by a 3" plank with a routed bullnose front edge. This is more attractive than not having it and provides some additional weather protection to that edge.
The planter is 8ft by 4ft with varying depth. 30 bags of miracle grow mixed with 10 bags of black soil later, and it's full.
A jiffy grow kit, some seeds, and a paper map of which seedlings are which keeps everything organized until they are big enough to transplant. Depending on the plant, some seeds skip this step and just go straight into the soil.
A few weeks after planting, things are growing well.
Looking quite decent after about six weeks.
Towards the end of summer, returning from a two-week vacation, stuff had got way out of control. I did learn some things in the process:
- Nobody really needs THREE seven-foot tall tomato plants to feed a family of four. One or two would have been plenty.
- Nobody really needs FIVE cucumber plants, we had hundreds of cucumbers and they aren't particularly versatile.
- Inspecting and watering a bed like this each evening is actually quite relaxing. Johanna usually enjoys that responsibility.
- The system performed awesomely but things were a little crowded, so I've been asked to build a second one this year, essentially 4ft x 4ft with no climbing headboard, just for lettuce.... but... then we have strawberries to consider, so it'll probably feature a stepped back with more planting room for the strawberries.