What do straw, paint brushes and the human blood circularity system have in common?
The answer is capillaries, very narrow, long tubes. It is this physical characteristic of straw which gives its remarkable ability to become the soil of a garden bed. Large amounts of water and nutrients can be held within the straws capillaries. This is an ideal environment for bacterial growth. This conversion from straw to soil makes nutrients available to plants.
During my time living in the foot hills of the Maluti Mountains which are part of the Drakensberg Mountains Range, located in southern Africa, I have made some great compost from the straw thatch of the traditional stone, mud and thatch roofed round homes at the Phelisanong community, where I was part of the Australian Government Aid, AVI programme in Lesotho as an Agricultural /Permaculture Advisor / Trainer.
There are a number of permaculture principles within Straw bale gardening including obtaining a yield and reusing elements. It also has benefits to people who have limited physical ability and garden resources.
Firstly straw bales are obtained, that is the stem of the crop such as wheat, oats and barley, after the seed is harvested. In Africa grasses suitable for thatching are grown on the food parts of the farm landscape such as the terrace edges. Straw bales can also be purchased from rural supplies and can often be obtained second hand from agricultural shows and displays.
The placement of the straw bale is important. The straw bales are placed on their sides with the string remaining on the sides. The cut straw side is placed on the top and the bent side placed on the bottom. The placing of two or three straw bales together makes for an ideal garden bed. Placing the straw bale on a weed proof ground cover, such as paper/cardboard and weed mat will prevent unwanted plant growth and allow water to enter the ground.
Over some two weeks the straw bales are soaked with water, urine, organic fertiliser, compost juices and compost teas. This is the essential proofing or conditioning process of the straw bale. Then a layer of weed free compost and or potting mix in applied to top off the straw bales. Seeds are sown in or seedlings are planted in the top layer. Water and organic fertiliser are added as required by the plants.
Once the plants are harvested the straw bales become a compost like material to be used in the garden. I am very impressed with the success of my first go at straw bale gardening. There is a high return for a low input with many side benefits. This could be part of the Permaculture way to ecological and economic permanence. I can thoroughly recommend straw bale gardening, it ticks all of the permaculture boxes.
I usually collect the straw bales left out the week after Halloween and set up the garden site, at that time, in the fall. The bales are topped with compost and left out in the snow and rain all winter and spring.
I found that the fresh straw bales composted too hot if purchased in the spring and not left out over the winter.
I have read that straw bale gardening requires more water, because the sides of the bales are open for evaporation. Did you find that to be the case?
I live in zone 7 in the United States. I did not have to water my plants extra. Average summer temp 90-100° The inside of the straw bale remained damp. I “top mulch” with 1 part cotton burr compost and 2 parts top soil, for direct seed planting. Inner to outer plants on bale will have different moisture requirements. I stay away from the edges. This forced me to buy more bales, but I can run the drip line down the center and conserve on water consumption.