From April to October, I conducted a crop production study with my students to compare the amount of basil produced by plants in a warmed plot and in an unwarmed plot.  Since the tulip and crocus bulb study was going on throughout April already in the raised garden beds in the OTC and fenced ambient temperature plots, the timing of this project worked out just right!  After wrapping up that study at the end of April, it gave me time to prepare the raised garden beds for the crop production study.  In preparation for the crop production study, I put in new topsoil for the OTC and fenced ambient temperature plots, fortified with compost from the upward migrating composting bin that I use in my classroom–donated to my classroom by a friend of mine from the Audubon Society.

At the beginning of April, my class planted basil seeds in our indoor garden so that they would be ready to be transplanted into the OTC and fenced ambient temperature plots by the end of the school year in early June.  I attained the indoor garden for our classroom through a Donors Choose Grant a few years ago.  It has UV lights and enough space to grow a moderate amount of plants.  For this study, I grew 72 basil plants for each of the plots.  As you can see from the photos, the basil plants grew steadily while they were in the indoor garden.

Here is one of the flats of seedlings just getting started growing on April 12:

And here is the same flat of seedlings on April 27 showing development of primary and secondary leaves:

Again, here is that same flat of seedlings on May 23 almost ready for transplanting for the outdoor raised garden beds into the OTC and fenced ambient temperature plots:

Just before the end of the school year at the beginning of June, my class transplanted the basil seedlings into the raised garden beds with 72 in the OTC and 72 in the fenced ambient temperature plot.  As you can see, I have a thermometer placed in the middle of each plot so that the temperature reading is always available to visitors.  Here is the OTC warmed plot (pictured first) and the fenced ambient temperature plot (pictured second) on June 1 right after transplanting:

And here are the two plots only a month later on July 3–you can see that the plants in the OTC warmed plot (pictured first) are already growing faster:

Here’s the first harvest on July 11 again with the OTC warmed plot pictured first and the fenced ambient temperature plot pictured second.  For a plant to be harvested, it must be in the flowering phenophase.  After processing (i.e. removing the unusable stems) the weight of the harvest from the OTC warmed plot was 20.1 ounces and the weight of the harvest from the fenced ambient temperature plot was 16.0 ounces:

Here’s another harvest on August 1 again with the OTC warmed plot pictured first and the fenced ambient temperature plot pictured second; now the production from the fenced ambient temperature plot has increased significantly.  After processing (i.e. removing the unusable stems) the weight of the harvest from the OTC warmed plot was 37.4 ounces and the weight of the harvest from the fenced ambient temperature plot was 47.7 ounces:

As the summer drew to a close, the production of the basil plants in the OTC warmed plot continued to exceed the production of the basil plants in the fenced ambient temperature plot.  On September 18, my students assisted me with the final harvest in which the weight of the harvest from the OTC warmed plot was 27.0 ounces and the weight of the harvest from the fenced ambient temperature plot was 50.3 ounces.  First, I taught the students how to identify the basil plants that were in the flowering phenophase since these were the ones that we would be harvesting.  As you can see, the student pictured below is correctly identifying a basil plant that is ready for harvesting:

Next, I had the students take turns harvesting the basil plants that were in the flowering phenophase.  We made quite a pile of plants to be processed, but the students worked diligently to remove the leaves from the stems.

Of course the stems are not part of the basil plant that can be used in the harvest, so those needed to be gathered for composting.

And the weighing of the harvest needed to be completed as well, so we traveled to the school district office to use their postal scale to determine the day’s harvest.

Our final crop production measurements for the entire project of processed basil was 160.0 ounces total for the OTC warmed plot and 230.2 ounces total for the fenced ambient temperature plot.  That’s a difference of 4 and 1/4 pounds MORE basil produced by the fenced ambient temperature plot!  We found in our study that our warmed plot produced more initially, but later in the season produced much less.  After the final harvest was over, the students helped me to clear out the raised garden beds for the end of the season.  We pulled out all the plants by the roots so that they could be composted.  The students were interested in making observations about the root structure of the basil plants.

Now that all the crops have been harvested, processed, and removed, the raised garden beds look a lot different!  It’s kind of a bittersweet ending to see all the basil plants gone, but I am looking forward to posting about the next part of the project–processing the basil into pesto for students and families from our school to eat!

• This topic was modified 6 years, 12 months ago by Kristin Joivell.
• This topic was modified 6 years, 12 months ago by Kristin Joivell.
• This topic was modified 6 years, 12 months ago by Kristin Joivell.