Wildflower mixes sprout weeds

Common wildflower seeds sold in little paper envelopes and let loose in yards could eventually engulf native plants, according to a recent report by the University of Washington.

The preliminary findings, which were released last month, have sparked a debate among government officials, local wildflower distributors and the researchers on what is legal versus what is the more responsible thing to do.

A student at the University's Center for Urban Horticulture grew 19 packets of wildflower seed mixes from around the United States and Canada. She found that each contained anywhere from three to 13 invasive species, and eight had seeds for noxious weeds — considered more destructive than invasive plants. A third of the packets listed no contents, and only five of the packets correctly itemized the seeds they contained, the student reported.

"I can't recommend using any wildflower seed mixes," said lead researcher Lorraine Brooks, who was an undergraduate studying environmental horticulture when she grew the plants from April to September last year.

Despite a federally mandated list of quarantined plants, there are additional lists on the county and city levels. In other words, what can legally be sold may not always be legal to grow in your own back yard, said Sean MacDougall, education specialist for the state Noxious Weed Control Board.

Plants are considered invasive if their spread overcomes other plants native to a particular ecosystem. Though it is not illegal to plant invasives, it is considered irresponsible by the gardening community. Noxious weeds, classified as such on state lists, are considered more destructive and difficult to control than invasive species. It is illegal to grow noxious weeds.

If someone is growing noxious weeds in their yard, the county noxious-weed control program may ask them to remove the invasive plant at their own cost. If they refuse, or don't do it within an assigned time frame, they may be fined, MacDougall said. Depending on the severity of the noxious weed, fines for the first offense range from $250 to $750. The fines compound daily. Locally, there are eight King County representatives who will come to your home to identify noxious or invasive weeds for free.

While researchers used a broad brush to decide what plants are considered invasive (they included varieties from every state and Canadian province), garden stores defended the right to sell varieties allowed in their state even if they weren't appropriate in another.

Brooks and Sarah Reichard, UW assistant professor of forest resources who supervised the research, say such a wide scope was used because plants considered invasive in one place are more likely to have the same tendencies in another. Therefore, gardeners should buy wildflower seeds species by species, making sure they are native to the region, rather than buying seed mixes, they said.

The 19 mixed packets studied were distributed by nine companies, including Ed Hume Seeds of Kent; Molbak's of Woodinville; Lilly Miller of Clackamas, Ore., which has since been acquired by Ferry Morse Seed Co. of Fulton, Ky.; Nature's Garden Seed Co. of Victoria, B.C.; and Burpee Seeds and Plants of Philadelphia. The study could be published as early as this spring or summer, Reichard said.

A noxious weed found in a mix produced by Ed Hume Seeds was dame's rocket, which is on Colorado's list of noxious weeds but not Washington's. Joe Hallberg, general manager of Ed Hume, said what may be banned in Colorado is perfectly fine to grow here, and given the different climates and environments, it's not a threat to native varieties.

"It's a wonderful flower," Hallberg said of dame's rocket, which he described as a pink, old-fashioned cottage garden flower. "Every state has its own list, and to say something is wrong in one area because someone else has it listed is really untrue and unfair."

Jane Wentworth, manager of the King County Noxious Weed Control Program, said she appreciated the study because it brought awareness to the issue of being a responsible gardener.

"If it's not invasive yet, it could (still) be added to the weed list," Wentworth said. "Why not circumvent the process or at least be aware that it could potentially become a problem someday? It would be nice for us to be on the same side of the issue. The more that we can recognize which plants are going to become invasive, the less likely it's going to be a problem."

Other company officials said they are concerned by the findings and plan to look into why mixes may have contained invasive or noxious species.

Molbak's spokeswoman Peggy Campbell said the company no longer sells two mixes that researchers found to contain yellow toadflax — listed as noxious in Washington, Oregon, Idaho and 11 other states and provinces.

"We feel very strongly about being responsible gardeners," Campbell said. "Every year, we take a look at product mixes and delete what may be new on the noxious-weeds list."

Campbell said she was concerned at how strict the study was for deciding what was considered noxious and what wasn't.

"I cringe at how broad-based the filter was," she said. "Because the University of Washington is in our own back yard, everyone assumes it all applies in total, and it doesn't."

According to the UW study, one of Nature's Garden Seed Co.'s mixes flowered nothing but invasive plants, even though it was labeled "native."

"Without further information regarding the study, it's hard for us to comment on the research," said Joan Goski, manager of Nature's Garden, which had two seed mixes cited in the study. "But we do stand by our products. We have really wonderful, reputable suppliers of all the seeds in those mixes."

Goski noted that each of the company's packages is seeded by hand, clearly labeled and approved for sale in the United States by the Department of Agriculture.

Burpee spokesman Dave Devine said his company makes every effort to keep invasive or noxious weeds out of its products. "We're a complete advocate of not spreading noxious weeds in areas where they don't belong,"' Devine said. Scott Whitehouse, vice president of sales and marketing for Ferry Morse, said every line of seeds his company sells is tested by independent laboratories.

"Certainly we would never under any circumstance ... put out anything that contains something it wasn't supposed to contain," Whitehouse said. "We want to get to the bottom of this as much as you do."

Information from The Associated Press is included in this report.