Susan Bloomquist, Peak to Peak.   Visions of blissful days relaxing in a warm light filled space with thriving plants all around; a greenhouse space is a controlled environment using the sun to heat and store heated energy to maintain a constant temperature. The temperature stays within a certain range, never too high or too low, very comfortable and stable for plants. People tend to like greenhouses too, as the atmosphere is humid and warm. It may be the difference between a greenhouse and grow house could be the use. A greenhouse could be a room for human habitation with plants, a grow house could have plants as the main focus.

When I grow want to grow a garden for food, I look for certain important elements for success. Access to water and good dirt are factors. The kitchen garden should be close to the kitchen, and protected from small animals and deer, so that the human in the kitchen gets much of the food and not the local wildlife. Many cooks have resorted to a closed space so they can be sure of the food supply. These supply grow houses can bring resilience to your life, not to mention delicious food.

A typical and inexpensive grow house can be established on the ground, built up with wood or stone walls and covered with a slanted clear cover. The strategy here is to increase heat and protect the space from animals and elements. To build one of these, start with some hardwire or chicken wire under the selected space. This protects from below, as voles are fond of vegetables. Build up a low wall around a compost bed. Surround the small grow box with low fencing and cover with an insulated grow cloth. Now, you have made a good start for your own kitchen garden. These box gardens can be any size and shape which works for you. You can place gallon jugs of water in the corners as thermal mass.

The factors important inside any larger structure of greenhouse are soil temperature, air temperature, and moisture.

The greenhouse structure must be translucent to let light and heat in, but this lets heat out at night. Even an insulated greenhouse loses heat and depends on thermal regulators available in soil, water and rock. The strategy is to have sections of thermal mass absorbing heat during the day and releasing the stored heat at night. The greenhouse must generate enough heat during each day to heat the inside of the structure and more heat to store in the thermal mass. Strategies exist to increase the heat inside the greenhouse and manage the extra humidity. The strategy of using SunnyTherm® solar collectors, for heating air and moving that heated air through a rock box during the day, increases the efficiency of the greenhouse by heating the thermal mass separately . So, the greenhouse uses all the gained heat of the day for the inside air, and the thermal mass is simultaneously heated using solar collectors.

The SunnyTherm® climate moderation system increases the heat available directly to the thermal mass. This strategy results in the thermal mass achieving much higher temperature during the day, leaving the daily heat of the grow house to the plants. At night, when the temperature drops, the thermal mass has gained much more heat from the solar collectors and can release it slowly. Increasing the amount of heat available at night from the thermal mass without decreasing the heat available during the day does wonders for the whole situation. The plants have warmer soil than air, which is better for root growth and sprouting baby plants. This extra heat does not cost extra on a daily basis because the heat is generated by the sun. The collectors can be located in a vertical straight line on the side below the line of translucence. The collectors absorb heat from the sun and reflected heat from snow. Location of collectors for a solar system is specific for each application, the modular form of the SunnyTherm® collectors provide multiple ways of assembling the 2’ x 2’ x 3” collectors. A general rule of thumb can be 10 collectors for 1000 square feet. The collectors provide significant extra heat directly to the thermal mass, providing dry heat and comforting hot rocks directly inside the greenhouse.

The Hotbox Grow House uses the SunnyTherm® climate moderation system in a small, personal application. The solar heaters are located vertically on the East and West sides of the 3’ x 3’ x 4-1/2’ grow house. Between the collectors is a steel box filled with rocks. The heat is absorbed into the rocks located at the base of the first level of the grow box. This heating system maintains an even temperature during the hot and cold fluctuations of temperature in the mountains. The lower level can be used as a seed starting bed or red worm compost. Both levels are warmed by the rocks.

The steel and hardware cloth protects on all sides and below from rabbits and deer and voles which can defeat all attempts to grow your own in this environment. The roof is removable for the warmer months allowing for pollination, rain and increased air flow available to plants. The elevated temperature is not contained in the air, it is held in the rocks and soil.

The Hotbox grow house can be compared to the Cold box inside your house, only the hot one produces food while the cold one keeps purchased food for your use. I like to call it an outside refrigerator, only it works for you for free.

BeeYond Gardening POB 1281, Nederland, CO 80466 * 303-258-7851 * beeyondgardens@gmail.com