greenhouse. This retired welder liked his liquor. Having more time
than money and little respect for legal absurdities, he had
constructed a small stainless steel pot still, fermented his own
mash, and made a harsh, hangover-producing whiskey from grain and
cane sugar that Appalachians call "popskull." To encourage rapid
fermentation, his mashing barrel was kept in the warm greenhouse.
The bubbling brew gave off large quantities of carbon dioxide gas.

The rest of his greenhouse was filled with green herbs that flowered
fragrantly in September. Most of them were four or five feet tall
but those plants on the end housing the mash barrel were seven feet
tall and twice as bushy. Why? Because the normal level of
atmospheric CO2 actually limits plant growth.

We can't increase the carbon supply outdoors. But we can loosen the
soil eighteen to twenty-four inches down (or more for deeply-rooting
species) in an area as large as the plant's root system could
possibly ramify during its entire growing season. I've seen some
GROWers dig holes four feet deep and five feet in diameter for
individual plants. We can use well-finished, strong compost to
increase the humus content of that soil, and supplement that with
manure tea or liquid fertilizer to provide all the nutrients the
plant could possibly use. We can allocate only one plant to that
space and make sure absolutely no competition develops in that space
for light, water, or nutrients. We can keep the soil moist at all
times. By locating the plant against a reflective white wall we can
increase its light levels and perhaps the nighttime temperatures
(plants make food during the day and use it to grow with at night).

Textural improvements from compost depend greatly on soil type.