Science and Math in the Kitchen Garden
Back in late March 2010 at Bungwahl Public School the children were very excited to start another experiment. Could they possibly grow summer vegetables through the winter? Looking at the different microclimates surrounding their solar passive chicken/kids' shed the question that stirred their thinking was……
"What do you think will happen to the rammed earth wall as the winter sun moves to its most northerly point?"
Our chook house provided the perfect opportunity for the children to look at how a solar passive building could create or enhance different microclimates within their garden. With the winter sun farthest north of us, our rammed earth wall is now absorbing the sun's warmth, heating up and re-radiating that heat into the ambient air surrounding the vegetables that snuggle up to it.
This heat also seeps into the shed through the wall and windows keeping ‘the girls' (chickens) protected and warm. Over the last few weeks our thermo-monitors (kids) have been curiously discussing and feeling this cycle of the sun while collecting data on a daily basis from thermometers they have carefully placed, in the shade, around and in the shed to look at the difference between these microclimates.
Week of the Winter Solstice Temperature Outcome: At Bungwahl School we have found that solar passive means solar passive. If the sun is hiding behind the clouds our thermometers all read within a couple of degrees. When the winter sun shines on a beautiful day, so far the largest difference between the suntrap and behind the shed has been 10 degrees, quite a significant difference.
Suntrap Experiment Observation So Far: So far the children are amazed at the visual difference between the tomatoes out in the exposure, compared to the ones hugging the rammed earth wall. These plants are covered in fruit and growing before our eyes. Our capsicum plant is also covered in fruit, the eggplant is covered with beautiful purple flowers, the basil is thriving and the marigolds are flowering, seeding and germinating all on their own. Our summer vegies are still powering. So far we have successfully trapped the sun.
With one month down and two to go, for how long will these vegies grow?
Interesting terms and meanings:
Microclimate: A microclimate is a small but distinctly different climate within a larger area.
Winter Solstice: 21st June, the first true day of the Season of Winter. On this day (DECEMBER 22 in the southern hemisphere*) the Sun is farthest north and the length of time between Sunrise and Sunset is the shortest of the year.
Nikki Dixon
Kitchen/Garden Specialist
Stephanie Alexander Kitchen Garden Program
Bungwahl Public School 
