When we arrived the left hand chamber was like a lush jungle. Radishes gone to seed were poking their flowers out of the ventilation hole in the top. The roots were still crisp and sweet, though. Bees were buzzing around the flowers.
Dori Cann and Scott Cole, caretakers at the Barcroft Station, said they had taken several harvests of radishes and salad greens from the cold frame left chamber in July and August and had made several salads.
Dori and Scott also told us that on August 7th they had a hard frost (low of 22 degrees F!) and that after that our gravity-fed watering system ceased to function properly – it just drained quickly instead of dripping like it should. Up to then, it had worked well. We will repair it and improve it in the Spring. For now, we left it disconnected and drained. The interior of the left hand chamber was quite humid, although it hadn’t been watered in almost six weeks.
We downloaded some temperature and humidity data from all three chambers, and harvested a LOT of radishes and salad greens from the left and right hand chambers. The plants in the right hand chamber (which has no window glazing) were much smaller, but they were alive.
The central chamber had been planted in potatoes. The potato plants were now dead above ground (probably they froze on August 7th) but below the ground we harvested a big bowl full of new potatoes. The variety is called “Alaska Frostless.”
We added some local sheep manure to the left and central chambers and planted them with a variety of winter wheat called CDC Falcon. We removed a portion of the window glazing from the left hand chamber.
Our work done (for now!), Matt and Cooper climbed 14,000’ White Mountain Peak. They saw two coyotes, a flock of bighorn sheep, and ballooning spiders and butterflies. George and Mike found some great examples of hypolithic cynaobacteria growing underneath quartz rocks. We also saw some amazing black-sky stars.
What we learned:
• The idea works!
• The Bayliss vents opening a window flap at the top of each chamber worked.
• The gravity-fed watering system worked for most of the growing season.
• The WMRS Staff are very supportive of this project.
Ideas for next season:
• Photovoltaic system with a 12-V sealed battery
• Rebuild the gravity-fed watering system
• Also build a pumped watering system – compare performances
• Plant: radishes, greens, potatoes, winter wheat, herbs? Calculate yield per acre.
• Convert the (no glazing) control chamber to a chamber that is glazed on the lower two thirds; open at top.
• Replace the Bayliss pistons
• Hook up a web cam?
We returned to our cold frame on White Mountain Peak to make repairs, improvements, and spring plantings
We almost didn’t make it. A late spring blizzard had dumped a foot of fresh snow on the site earlier in the week. By the time we got there the sun was shining and the snow was melting.
The frame was a little beat up from the winter. Part of the hardware cloth rodent-fence was torn off, and the middle window frame was warped and ajar.
A surprise awaited us when we opened it up. The plastic garden thermometer in the right chamber (the one that was sealed tight) had melted! It looked a lot like one of Salvador Dali’s clocks. When we checked the data logger in that chamber we learned that the temperature had exceed 185 degrees F. As Matt pointed out, water boils at that temperature at this altitude! No wonder nothing was living in this chamber. So, we learned that ventilation on hot days is crucial.
Fortunately, we came prepared for this. We replaced the left and central chambers with windows that have much stronger frames and better ventilation systems. We also added analog minimum/maximum recording thermometers and a gravity-fed drip irrrigation system with a 75 gallon capacity.
The data loggers also recorded high temperatures of 165 degrees F in the middle chamber and 112 degrees F in the chamber that had no window glazing! The last measurement was simply impossible to believe. Belatedly, we realized that all three of our blue plastic data loggers were exposed to the direct rays of the sun. They had given us readings that were too high.
How could we have made such a simple mistake? But, live and learn. We build little sun shades for our data loggers out of reflective bubble wrap.
Most of what we had planted last August in the middle chamber had sprouted and started to grow, but it was all dead now. Or was it? A close examination of the brown tufts of winter wheat revealed green blades. We left the winter wheat to try to recover in its new cooler and moister environment. We also planted radishes, assorted salad greens, marigolds and a variety of potato called “Alaska Frostless.”
What we learned:
Extreme heat is more of a problem than extreme cold. Ventilation is the key to success. It got so hot in the sealed chamber that water would have boiled.
Nothing grew in the unsealed chamber, so the window glazing does help maintain an environment suitable for plants.
We have to keep our thermometers and data loggers in the shade (we ought to have known that.)
We don’t seem to have any trouble with rodents.
Our MicroDAQ data loggers worked great.
All three chambers recorded approximately the same minimum air temperature (-5 to -9 degrees F), so we need some way to better heat or insulate the chambers on cold winter nights.
Winter wheat shows promise for a fall planting.
Our work done (for now), we enjoyed campfires at the University of California’s Crooked Creek Facility (elev. 10,000 feet) and went for walks in among the bristlecone pines. We’ll be back in September if not sooner.
In August of 2008 students from Sir Francis Drake High School built an insulated cold frame at the University of California’s White Mountain Research Station (elevation 12,470’)
This one is higher than any other test plot, greenhouse, cold frame, farm, or garden in California. In fact, it may be the highest cultivated place in all of North America.
Our team consisted of Monica Dreitcer, Matt Gabel, Meredith Goebel, Christine Quach, Mika Weinstein (students), Ray Goebel (parent) and Michael Wing (teacher). We installed it August 14-17, 2008. (We slept and ate at the UC’s Crooked Creek facility (elev. 10,000’):
We also saw the ancient bristlecone pines and climbed 14,246′ White Mountain Peak.
This project was featured on the front page of the Marin Independent Journal on September 4, 2008.