The Ministry of Forests Plastics Working Group is recommending planting contractors hold back from any major purchases of cornstarch flagging dropped to mark seedlings until further research of the product is completed. Preliminary testing, so far, indicates the bioplastic fabric does not break down readily when exposed to ambient temperatures and sunlight or when soaked in water or mild acids. In addition, research needs to be completed to assess if cows can digest the stuff, given its apparent durability and composition.
The rough science experiments used so far are consistent with the well-researched behaviour of polylactic acid; the primary molecule involved with plant-based plastics like cornstarch flagging. It is biodegradable, but only at high temperatures more typical of commercial composting operations (140 °C). This would explain the flagging’s seeming resistance to normal weathering.
In some cases, industry and government agencies are banning the use of both regular and starch-based ribbons in planting contracts and instead opting for no mark planting altogether. WFCA recommends members check with their clients regarding the status of drop ribbon use for this coming year’s planting.
Nevertheless, the cornstarch flagging may be acceptable in replacing the petroleum plastic ribbon used to mark boundaries and related survey work. Elevated, tied-up ribbons away from grazers wouldn’t present the same threat to the BC cattle herd or some wildlife. It appears the material may be able to hang out for seasons according to ongoing experiments with last year’s cornstarch flagging. Reportedly, the plant fabric is printable, adding to its potential utility. Flagging for this application is a much larger national market than for marking seedlings.
It still would be useful to determine if the fabric holds together in normal operating conditions for planting work. We are hoping contractors will test some flagging this year while we continue to test and verify our initial research findings.
The Ministry of Forests Plastics Working Group is a consortium of forest licensees, cattle ranchers, the WFCA, and various government agencies with jurisdiction over wildlife, ranching, water, forests, and the eventual elimination of single-use plastics in forest and seedling nursery activities.