Extending the vegetable growing season with low cost quick hoops
We used several configurations of row cover this year, including row cover on hoops, double row cover, and cover directly on the ground. We used funds to purchase row cover, shade cloth, hoops, and sandbags, and to reimburse labor for the experimental applications.
Last summer our attempts to grow head lettuce under shade were unsuccessful, but we’ve discussed with other growers, and feel that we’ve got some good ideas to go forward with this year. This winter was a real anomaly, with temperatures rarely below 20 degrees F. and spring-like conditions beginning in January… so our results are not very conclusive yet. Some of our crops which were totally out in the open did almost as well as crops under row covers, which is inconsistent with our previous experience. In the past, yields of marketable produce [grown] under cover were much higher. Possibly contributing to this phenomenon this year is the fact that we also had a very dry winter. Often times the soil under the row covers was quite dry, and we were not prepared to water them, as we’ve never needed to water outside row-covered beds in previous winters. This likely slowed the plants under cover. This summer we are installing several shade cloth low tunnels to grow lettuce and spinach, and we’ll be monitoring soil temps and growth rates, as well as how well the crops resist bolting.
So far, we’ve learned that shade cloth is considerably more difficult to attach to low hoops than row cover, and we’ve gone through several different permutations of attachment systems. So far, I’m really not happy with any of them; they’ve all blown off at least once a week, leaving the plants exposed to the sun. We have some ideas this summer; partly generated by visiting Patrice Gros of Foundation Farms, which we hope will keep the shade cloth in place. On the other hand, we feel very confident that we’ve figured out the structural details on the floating row cover low tunnels; our tunnels are staying put, and intact, despite high winds and ice and snow.
We’ve learned to lay everything out as straight as possible, to insert the legs of the hoops deep into the ground using a pipe wrench as a camming device, latching onto the pipe about 8 inches above ground level and then stepping on it. This really sinks the hoops well, without deforming them, and we’ve had hoops put in this way hold up very well to any degree of wind. Next we lay the row cover out next to the hoops, and attach it to stakes driven deep at each end of the tunnel, at least 6 feet from the last hoop, and cinch it tight from one end to the other before pulling it across the hoops. This seems to be the key we were missing in the past; the end to end tightness really seems to protect from flapping, which is the enemy of row covered low tunnels.
Next we spread the cloth across the hoops, and lay a sandbag full of compost at the base of each hoop on each side to weigh down the row cover. Using this procedure has virtually eliminated covers blowing off, and now the only real problem we have is that if anything starts to tear the cover, it is difficult to keep it from ripping across the whole thing. Another result from this year was that due to the extremely warm winter and spring, we were caught off guard and probably should have removed covers from late planted kale much sooner than we did; as a result, we were only able to harvest a couple of times before they bolted.
WORK PLAN FOR 2012
We will continue to use low tunnels to protect crops from extreme weather, using shade tunnels this summer to grow Asian greens mix, lettuce mix, head lettuce, and spinach.
Next fall we hope to cover as much as .5 acres with low tunnels, starting in October, to carry fall crops in the winter, and try to over winter late-seeded carrots, spinach, beets, and kale. We continue to be very optimistic about the possibilities of low tunnels, having seen the benefits first hand. We will also be more diligent about keeping yield records for our low tunnels, to determine the cost/benefit ratio of the low tunnels versus other ways of growing.
We’ve hosted over 120 individuals for learning experiences on the farm this year. Last spring, as our season was just getting started, we hosted a tour of our farm for the Missouri Organic Association, which included a one-day seminar at a local conference center, followed by a tour of the farm in the afternoon. We had about 30 people in the morning class, and about 25 attended the farm tour in the afternoon. We also hosted two full-time interns last summer, as we are this season, along with 4 part-time interns. We also presented at the Nebraska Healthy Farms and Rural Advantage Conference in Nebraska City in February of 2012. At each of these venues we’ve highlighted our work with low tunnels, and have had good discussions with other growers who are trying these as well, or who will try them now, having seen our farm or pictures. We intend to attend the Small Farm Today Conference and speak in the Farmers Forum this year, in November. We also will be hosting a number of farm field days, both for the general public and other vegetable growers. I expect that we will again have a couple of hundred participants.