Here is a quick recap of what went on at the Farm to YoUNH high tunnels this past spring:
The growth habits (including time to germination and time to harvest) of greens mix and lettuce mix was studied. We were working to determine the effect that planting in the heated versus unheated tunnel had on the crops. We also studied how the crops’ growth habit is changed as we plant later in the winter (closer to the conventional growing season).
Though we faced many setbacks and did plenty of troubleshooting along the way, we were able to formulate some interesting results. First, let’s discuss the problems. Craneflies were a huge pest species not only for the experimental lettuce mix plots, but all of the lettuce mix being grown in the tunnels. Craneflies are known for their destruction of seedlings. After multiple attempts, we were able to get the cranefly larvae under control… just in time for the winter tunnel flooding to commence. Flooding in and around beds caused the growth of algae and fungi, which can be detrimental to crop germination and growth. Further, saturated soils do not allow for proper gas exchange. Salinity also appeared to play a role in the many, MANY crop failures that we experienced. On multiple occasions, we had to remove plantings from the trial due to extremely poor germination rates.
All of these problems aside, we were able to determine that time of planting did not affect lettuce germination time, greens germination time, or greens harvest time. Time of planting did affect lettuce harvest time, though only in the heated tunnel; time of planting did not affect lettuce harvest in the unheated tunnel. Heating the high tunnel did not have an effect on lettuce germination time, greens germination time, or greens harvesting time. It did, however, affect lettuce harvest time.
Another interesting thing that we noticed in our experiment was that the greens perform significantly better than the lettuce mix when being grown during the winter. While the seed company suggests planting the lettuce mix a week prior to the greens mix in order for both to be harvestable at the same time, we determined that for winter growing, the planting gap should be around 12 days instead of one week.
These results are not what we expected, but are incredibly interesting nonetheless, and will hopefully spark further research into the growth habit of one of Farm to YoUNH’s favorite crops, salad mix.