In an effort to increase our salad greens we've built two experimental covered raised beds. They're rather fancy. They have a clear plastic roof which is sloped to allow more direst sun in and to allow us to harvest rainwater. The roof is high - again to allow more direct sun to hit the plants, and stands about 8.5 foot at the higher end, about 7.5 foot at the lower end. We plan to make use of this space by using baskets or trellis for vertical growth.
The beds are built on a very slight slope and run across the slope to give the most exposure to sun. We have a lot of big trees on the farm and finding an area which has full sun is no longer a simple matter, hence we plant with the direction the sun takes, in both summer and winter months, in mind.
The roof allows us to control how much water the plants receive: meaning we can try to grow varieties which typically won't stand our rainfall.
The frames are constructed of kasha wood from a tree that fell on the upper farm. It's a beautiful hard wood from a beautiful leguminous forest tree. We put down a thick layer of coconut fiber for drainage. Coconut fiber takes a long time to break down and will help create a decent environment for worms and beneficial microbes. For the lower bed we mixed coarse sand, compost and new earth dug up from beneath a rotting tree trunk. For the upper bed we used a mix of coarse sand and soil made by mixing coconut fiber, compost and aged chicken manure. (This soil came from a local company who also make coconut oil and noni juice, they buy their chicken manure from a friend of ours who raises organic chickens, the compost is made from restaurant food scraps.)We put a fine layer of coarse sand on top and then treated the beds with EM, leaving them to settle in for 5 days or so.
I've been pulling weeds from the lower bed for the last 8 days, it looks like seeds from our own composting: tomato, chili, squash. I've saved some of these seedlings and the others I've composted. The upper bed has been weed free, making us wonder if the soil was sterilized.
We sowed eggplant, broccoli, bok choy and radish. We also have a few tomato starts, some rooted cuttings of mint and purple basil, some purslane, chilis we brought back from Cuba and some cranberry hibiscus sticks.
At the far end of the beds we have a large basin with water hyacinth. This is our mulch material, we currently have some drying out under the roof almost ready to add to the soil. Water hyacinth makes excellent mulch, composts rapidly and is a prolific grower. This one tub will provide us with as much mulch as we'll need for this project. Beside it is a tub with watercress, rooted from cuttings. Actually rooted from some watercress we bought at the farmers' market (the mint and basil also came from stalks we bought at the ferria).
The seeds came up in 5 days and are looking good. I thinned them, transplanting some and harvesting the rest for salad mixes. The tomatoes and chilis look fine, and the mint and basil seem to be rooting out given their colour and vigour. The tomatoes and chilis I expect to do well, they grow here without special attention. The brassicas, well we'll see. The eggplant - would be wonderful, it's my favourite vegetable. I think the mint and basil will make it with a roof, especially if we are careful with not letting them get leggy. We'll continue to use EM to keep molds and fungus at bay. I'm excited. It seems funny having to water in the midst of all this rain, but it's easy enough to do. And it would be so worth it to add to our salad options.