Friday, March 7, 2014

Hurry up and melt

That mostly sums up my state of mind.  Snow is melting, finally.  I’m thankful for the relative warmth, something that was just a glimmer in my mind for many weeks, but it leaves a mess.  The top few inches of soil are thawing while the soil beneath is still frozen hard.  Temporary permafrost?  At any rate it is way better than the deep freeze.  Of course the pond is still covered with snow and ice and a web of animal tracks.  I’m speculating when the first open water will appear, maybe next week.

I seeded two trays of onions on Feb. 20 and have been itching to get them out into the mobile coldframe.  They are long day onions and while they are under the lights indoors the light period is matched to the sunrise/sunset times, about 11.5 hours of light right now.  Since artificial light is not nearly as intense as sunlight the seedlings really need a few more hours of light to compensate.  The weather forecast suggested that Thursday was the day to move the onions outside.  
There’s a temperature sensor inside the coldframe and another outdoors that let me monitor the environment in the coldframe and compare it to the outside temperature.  A week ago a sunny day with a high just over 40 F the temperature in the coldframe went over 100 F (no plants inside of course).  It’s definitely an efficient retainer of solar energy.  The stones inside help hold the heat overnight, but when the outside temperature goes into the single digits the inside will get far nearly as cold by morning. 

 Shortly after noon on Thursday, a sunny day, the outside temperature was 43 F.  

The temperature inside the coldframe was much higher, over 80 degrees and climbing.  

I opened the lid to the first setting and continued to monitor the temperature.  The temperature dropped and stabilized at just over 70 F,  perfect for the onion seedlings.    

The trays of onion seedlings were set in the coldframe.  The earthbox will be planted in lettuce when the seedlings are ready.  Later in the afternoon when the sun is at an angle to the south-facing glazing the lid will be shut to hold the warmth for the night.  I’d like to get a temperature activated opener for this but for now the work must be done by me. 

Now there is more room under the flourescent lights for new plants.  It’s possible to put 4 trays underneath the lights by setting the trays crossways but I have to raise up the lights so all of the plants get light, and that dilutes the light intensity.  With the onions outside the remaining two trays can be aligned with the light fixture and the lights can be lowered right over the plants.   

1 comment:

Mark Willis said...

Your garden-protection hardware must be very welcome at times like this!

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