garden:infrastructure:lowtents:temps
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garden:infrastructure:lowtents:temps [2020/06/28 20:11] – created davidbac | garden:infrastructure:lowtents:temps [2020/06/28 21:12] (current) – davidbac | ||
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+ | ===== Temperatures ===== | ||
+ | ==== Extended growing ==== | ||
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+ | I use the low tents to extend the growing season for suitable plants-those that have some cold tolerance but which might be killed or stunted by a hard frost. In 2015 I grew mostly lettuce, chard and bunch onions in the tents. Lettuce transplanted on April 3 did remarkably well. We harvested for the Food Pantry throughout June. | ||
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+ | I put plastic on the tents in late March and keep it on until temperatures warm enough and the threat of frost is gone, through May. I put the plastic back on in late September and leave it on until the plants are done. | ||
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+ | ==== What's this for? ==== | ||
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+ | {{ : | ||
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+ | I collected the following data to answer some important questions about growing in the low tents: | ||
+ | * When do I need to open the tent to the outside environment to avoid baking the plants (given a forecast for clear skies and an expected temperature)? | ||
+ | * Given a forecast low temperature, | ||
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+ | So the exercise described here wasn't an abstract science experiment, but an attempt to find successful growing parameters in the low tents. | ||
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+ | I collected temperature (as well as humidity and solar radiation) data outside with a nearby weather station and inside by a Tempo Environmental Monitor inside the tent. I choose readings every 30 minutes for the average temperature during that period. | ||
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+ | I collected similar data for the hoop house, but I haven' | ||
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+ | ==== Soil temperatures ==== | ||
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+ | In November 2015 soil temperature outside the tent was 54 degrees about the same as in late September. | ||
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+ | Inside a tent without row cover the soil temperatures was 57 degrees. Soil temperature under the row cover was slightly warmer (after one week) at 58 degrees. | ||
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+ | ==== Typical differences ==== | ||
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+ | The low tent traps the sun's rays during the day and the temperature inside increases, up to more than 15 degrees in the fall season. On a clear day I would open the tent in early afternoon and then close it around 3:00 to avoid a temperature greater than 90. | ||
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+ | The tent's plastic is not insulation so at night the inside temperature is generally only 1 to 2 degrees warmer than outside, except under additional row cover laid over the growing plants. | ||
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+ | This graph compares the outside temperature with the temperature inside the tent. Generally the difference is greatest when the sun is shining. | ||
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+ | {{ : | ||
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+ | ==== Row cover ==== | ||
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+ | {{ : | ||
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+ | The row cover mitigated the effect of sunlight during the day slightly reducing the warmth around the plants. Notice on the morning of 11/5 the temperature under the cover was 7 degrees warmer than the outside temperature, | ||
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+ | ==== Under cover ==== | ||
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+ | This graph shows typical temperatures of November weather from sporadic sunshine with rainy, overcast days. | ||
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+ | {{ : | ||
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+ | ==== Average difference ==== | ||
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+ | During the Fall of 2015 the average outside temperature was 53.9, the average inside temperature was 57.2. That is for every half hour over that time. | ||
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+ | ==== With little sun ==== | ||
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+ | I had two low tents in the garden that receive all the sunlight that there is - they are not shaded. | ||
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+ | At home I had two raised beds that received sunlight for only about 3 to 3 1/2 hours, when the sun shined. | ||
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+ | Growth of plants at home was markedly slower than at the garden. I had cabbage in the tent at home and cabbage in the open at the garden. At home the cabbage was spindly and not forming heads after a month, while at the garden they were a bit stockier and just starting to form heads. It is clear, however, that growth with limited sunshine is greatly retarded. (No surprise, but I though maybe the cabbage in the low tent might keep up with those at the garden in the open. |
garden/infrastructure/lowtents/temps.txt · Last modified: 2020/06/28 21:12 by davidbac