Farm staff Richard and Tom are busy overseeing the Teen Ag Program and vegetable garden this summer season. Tom’s science-rich talks are found each week in the CSA Newsletter. Read this week’s Tom’s Talk to learn about how the Teen Ag crew keeps their weeds at bay.
By Tom Prohl
We are in full swing with growing our vegetables and small fruits up at the garden plot, which has quickly grown in size this season. As vegetable production increases, a weed management plan is necessary to keep weed growth and reproduction under control. I will outline the strategies we are implementing and plan to implement this season:
Shifting Cultivation We are shifting cultivation to areas which have not yet been used for vegetable production. This will let the heavily-farmed areas with intense weed pressure “rest” while we use a cover crop, such as Sudangrass or Buckwheat.
Cover Cropping Intensive vegetable production leads to a buildup of weed seeds in the soil, also known as a “weed seed bank”. We plant a crop of buckwheat on areas with bad weed pressure. The cover crop has the ability to grow more quickly than the weeds, which will smother the weeds out. These crops also add organic matter to the soil, attracting beneficial insects and pollinators. We then turn the crop in before the weeds growing in the understory of the buckwheat have a chance to go to seed.
Solarization Reusing old greenhouse plastic to cover the soil essentially bakes the soil at high temperatures during the heat of the day. The heat produced “cooks” the weeds that’ve gone to seed and is very effective in killing them. The downside to solarization is that everything in the soil is killed — both the good and the bad.
Reducing Tillage We are making a real effort to reduce tillage this year, and some advancements in our equipment will help make this a possible endeavor. Thanks to the generosity of a Harvard Pilgrim Health Care grant, we were able to purchase a new cultivation tool that provides lower impact weed control options. Tillage is a great way to kill weeds, but it is rough on the soil and it brings the seeds of weeds to the surface where they can easily germinate.
Mowing Weed control doesn’t just stop in the garden; the edges of the field are just as important. In addition to weeds going to seed, the edges of the field are often a refuge for insect pests who live amongst the dense weeds. The pests travel into the field to damage the vegetables, such as potatoes and cucurbits. This year I have been mowing and weed whacking the edges of the field to keep the seeds of weeds from blowing in on the nice afternoon breeze!