Germination Chamber

We are starting to germinate seeds for the new year in our heated hoophouse. We are keeping the temperature overnight at a minimum of 50 degrees. Maximum temperature is maintained at 80 degrees during the day by cracking the door open when the temperature passes 80.

Seed Germination Chamber

This year we decided to try using some of our coolers rather than the large insulated box we used last year. The heat source is a string of 100 conventional Christmas tree lights which use about 240 watts of power. These lights were on sale just after Christmas for only $1.25 a string and one string can provide heat to two coolers.
We put a web tray in the bottom of the cooler to make sure that the lights would be above the bottom in case there happened to be any standing water in the cooler - wet lights could be hazardous to the operator! We bought an
inexpensive digital themomenter at Menards for about $7 and put the probe into the bottom of the cooler. We added lights a few at a time until we could maintain a nighttime temperature between 75 and 80 degrees. It took about 25 of the little lights to keep the cooler 25 to 30 degrees above the ambiant temperature inside the hoophouse. We open the coolers in the morning to check the status of the trays and tubs and remove those that have started to germinate. Everything gets just a bit of water on the top to make sure seeds are moist.

The results have been pretty good and some of the greens have begun to germinate in just 24 hours! By the end of the day we'll have three coolers going and one will be maintained a bit hotter for peppers and tomatoes -- we're beginning to plant some of these to grow large enough to fruit to sell at spring markets.

There are a couple of things to watch for. First, if you take a partially germinated tray out in the morning, it should finish germination but it should be watered twice a day to keep moist. If you leave it in the cooler, you run the risk of some really leggy plants. When we get leggy ones we have been sprinkling a bit of potting soil to reduce the length of the stem. It's also a good idea to do a quick check in the late afternoon to see if any trays or tubs need to be removed.

We have a pretty bad mouse probem so any partially germinated trays need to be covered or placed in an inaccessible place although the mice seem to be able to go just about anywhere! They seem to prefer spinach, sunflower, and cilantro seeds and also baby lettuce seedlings. We are testing various kinds of traps to see which ones work the best.

















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