greenhouse – Montessori Muddle

First frost

greenhouse-reset — Transporting plants into the greenhouse.

The temperature dropped below zero (Celcius) for the first time last Friday night. We’d put back up the greenhouse’s plastic cover, which had blown off a couple weeks ago in a wind storm, but that was not enough to save a couple tomatoes and a squash plant.

It was a good illustration of the effects of freezing on plants not adapted to the colder weather. The leaves all turned black and flopped over, probably because the expanding ice ruptured the cell walls.

It also indicates that I need to get at temperature data-logger so I can monitor the temperature inside and outside the greenhouse. In the spring I hope to start a bunch of plants inside but put them into the greenhouse at the first opportunity, but I’ll need to make sure that greenhouse can support them. The data logger will also allow for some interesting experiments.

Resurrecting the greenhouse

Two years ago, the middle school’s flagship project was to put up a fully functional greenhouse (using this design). It took all year but we did it. On the way, we got to practice geometry, mapping and construction, while learning and growing plants and studying soil profiles. It was so successful that, with our spring plant sale we broke even on the entire project.

Last year, however, the greenhouse was somewhat neglected. My plans to add an automatic window opener, which would have been a wonderful tie-in to our electronics and Newtonian physics studies, did not work out; we just did not have the time. We’d taken the plastic covering off, so only the bare, forlorn PVC frame was left standing around a plot of waist-high weeds.

Though I could not have predicted it, this year we have a strong core group of students who are highly enthusiastic about resurrecting the greenhouse and making it work. My suggestion was that we try to grow produce this fall that we could cook in December when we do our Dinner and a Show. Well, two weeks in, they’ve already put together a menu plan, weeding is well on its way and I’m being harassed to hurry up and arrange a trip to Home Depot. The excitement is so infectious that another student has volunteered to bring in his electric weed-whacker during the immersion. It’s amazing!

I’m having the hardest time not butting in. There is a beauty in seeing a well oiled machine executing a project or solving a difficult problem. But there is another even more wonderful aesthetic visible in a the birthing struggles of a nascent team. The forward motion of infectious enthusiasm is pulling puzzle pieces into its wake, and the pieces just seem to click into place when the time is right. I have to keep reminding myself that my job is to prepare the environment and let the kids do the rest.

Help with gardening/greenhouse

The National Gardening Association website has a wealth of resources for managing a garden. Including regional reports:

For the middle-south, “With year’s hottest and driest weather just ahead, it is best to delay the planting of tress and shrubs until autumn, when the odds of successful establishment are more favorable.” – St. Claire, 2010

They also have some nice how-to videos and instructional pages on topics like planting tomatoes and starting vegetable seeds (for the plant sale).

Osmosis and strawberry shortcakes

Osmosis is the movement of liquids through a membrane, from areas of high to regions of low concentration. So, if you sprinkle sugar onto ripe strawberries, the concentration of sugar on the outside of the berries becomes very high. The juices will seep out of the strawberries’ cells, through the cell walls (the membrane), and create quite the delectable syrup. Add a few shortcakes and some whipped cream and ….

strawberry-shortcake — Strawberry shortcake (gluten free).

Note to self: try strawberries in the greenhouse this winter. Life sciences are next year and osmosis is a key concept.

Note #2: This is also a large part of the answer to the question of, “Why do we get thirsty when we eat salty foods?”

Experiments with seedlings

Next year we’ll be focusing on the life sciences, so this year one of my student’s research project was to try to grow some plants using the system we’d set up the year before to see how effective it was and to find out if we could use the plants we grow for a plant sale at the end of the year. I also started some plants at home as did the student’s parents, which served as a reasonable control.

We learned that you have to account for the different germination times for different plants, and the importance of hardening plants off before taking them outside. We also learned that the greenhouse can get too warm in the spring. While the plants we started at school were not the most successful, it was an extremely useful project nonetheless, otherwise we’d probably have made the same mistakes next year. A pair of temperature/humidity data loggers, for inside and outside the greenhouse, will be extremely useful for monitoring growing conditions.

The big land-grant universities have fairly good extension services that have a lot of good information online. The University of Missouri’s page on Starting Plants From Seeds is quite useful, although it is not aimed at the organic gardener.