Published July 18. 2013 4:00AM
Griswold - In an overgrown field at the research farm, waist-high leafy green stalks marked with small colored ribbons grow amid horseweed and daisy fleabane, looking neither the aggressive invader nor the unfairly demonized organism some people purport it to be.
"You've got passionate people on both sides, and we're trying to provide some objective information," said Jeffrey Ward, chief scientist in the Department of Forestry and Horticulture at the Connecticut Agricultural Experiment Station, stretching out a stadia rod one morning last week to measure one of nine yellow groove and golden bamboo plants growing at the agency's farm since May 2012. "We started this project because of questions by the state's Invasive Plant Council about how big it could get and how far it could spread. No one really knows. This is basic science."
Particular varieties of this Asian grass have sparked fierce controversy in the state. Some residents say bamboo planted on neighbors' properties has leaped over onto theirs, its roots and rhizomes damaging foundations and septic tanks, leading to costly repairs and extensive removal efforts.
On the other side are landscapers and homeowners who appreciate it as a fast-growing, deer-resistant natural fence, and have argued against a ban. That debate came to the state Capitol in the most recent legislative session, resulting in a new law signed by Gov. Dannel P. Malloy June 5 that prohibits the planting of certain varieties of bamboo unless they are 100 feet or more from the property line or contained in a barrier. It also makes growers liable for damages and removal costs on neighboring properties.
While waiting for the new law to take effect Oct. 1, advocates of a ban have been keeping up their campaign. This summer, proponents of the ban are visiting town halls including those in Preston, Norwich and East Lyme to advocate for local ordinances prohibiting bamboo.
Ward, for his part, isn't taking sides.
"My recommendation now is that people follow the law, and have it contained," he said. "It can provide a wonderful landscape feature as long as it's not going into your neighbor's yard. Every plant is a weed when it's out of place."
The multi-year research project is monitoring the growth habits of two of the most popular bamboo varieties at the experiment station's research farms in Windsor and Hamden, as well as the one in Griswold, so it can be assessed under different soil and moisture conditions. Maps are being created that will show the annual growth of each plant.
Ward is also testing different techniques to contain the plants' growth, having some plots mowed regularly, applying herbicides to some new shoots and keeping some of the bamboo contained within chambers of heavy plastic. The plastic is placed 8 to 10 feet around the mother plant and 30 inches below, to prevent the rhizomes - underground stems that send up new shoots - from extending too far. The plastic also juts several inches out of the soil, because the rhizomes have been known to climb over shorter barriers, Ward said.
"But no one's done an experiment to see if it (the barrier) really works," he said. "For homeowners who want to legally plant it, we'd like to be able to tell them how fast it grows, and whether mowing or containers are an effective way of controlling it."
Just a little over a year after the project began, Ward is already finding a few surprises. Last week, when he visited the Griswold farm to measure how much the bamboo had grown since he planted it last year, he found that most had spread 5 feet or less from the original plant. Just as he was packing up his stadia rod, measuring tape and clipboard, he paused to take a last look at one of the yellow groove plants.
"Look what we missed out here," he said, walking toward a lone young shoot, nearly obscured by weeds. He measured the distance to the mother plant.
"This is a new stem coming up. It's 1.8 meters (6 feet) from the center," he said. The rhizomes, he said, grow underground the previous year before the new shoot emerges from the ground the next spring. That meant the bamboo extended out that far the same year it was first planted, when it was probably still experiencing some transplant shock.
"What's amazing," he said, "is that that means the roots grew out to here last summer, before the shoot popped up."