December 14, 2011 journal

Four replacement Little Leaf cucumber seedlings have been replanted into autopots. Two will be grown using a red/blue 90 watt LED light, and two will be grown using a red/blue/white 90 watt LED. I do not expect to see any appreciable difference in the performance of these lights. And, I do not expect to see any cucumbers until around Valentine's day. (keeping my fingers crossed)

I have been noticing that the Balcony Hybrid tomatoes in the tent are not making much progress. There are a lot of green tomatoes, and they seem to be getting larger, slowly, however, there is no sign of any of them ripening anytime soon.

Winter is upon us in upstate New York; the temperature in the tent is averaging in the mid sixties during the day, and dropping to the mid fifties during the night. According to the Ohio State interactive model, maturing tomatoes should have a daytime temperature between 72 and 75 degrees. I am convinced that the reason that growth has slowed to a trickle is the lack of warmth. After all, tomatoes, like cucumbers and peppers, are warm season crops. I had thought that the lights would provide sufficient heat during the day, but, being LEDs, they generate little heat.

In search of an inexpensive means of adding heat to the tents; I wandered around Wally World looking for SMALL fan forced electric heaters. The units I selected cost under fifteen dollars, and seem to be exactly what I need. They have a thermostat, and power selections of 600, 900 and 1500 watts. Additionally, they have a fan only setting, which will allow me to remove the small circulation fans I currently have in the tents.

Not being too concerned about the nighttime temperature, I connected the heaters to the timer circuit controlling the lights. Using the lowest, 600 watt, setting, I adjusted the thermostat to 75 degrees. A remote thermometer has been placed in the tent with the tomatoes, and the temperature is now averaging between 70 and 77 degrees, which is about ideal. The relative humidity is also well within the acceptable range, so, hopefully, I will see an increase in growth rate soon.