Question: I purchased a filled thistle sock from you at a Texas bird festival. When I got home my husband said that thistle seed makes tumbleweeds and that I shouldn’t use the thistle sock because Russian Thistle is an invasive plant that should be exterminated. Is he right, am I planting tumbleweeds when I feed the goldfinches?
Answer: This is not the first time I have this question from people who start using ”thistle” in their finch feeders. The confusion comes in the terminology. What I sold you is Guizotia abyssinica, an erect, stout, branched annual herb originally from the Ethiopian Highlands. The common name there is nigernood, which translates to the blackseed. When the seed became a cash crop, and exported to the U.S., companies changed the name of the blackseed to thistle seed to cash in on the finches affinity for native thistle (not the invasive thistle your husband is referring to.)
Later the Wild Bird Feeding Industry (WBFI) has trademarked the name Nyjer. Their goal is to have the seed referred to as Nyjer so as not to confuse it with Russian Thistle. They felt a spelling change was necessary to avoid any thoughts of a racial slur.
Before you purchase Nyjer for use in your thistle feeder, the seed is heated to 120 degrees for 15 minutes to sterilize the Nyjer seed. This insures that you may fill your “thistle feeder” for your Goldfinches, Pine Siskins, Redpolls and Purple Finches and not spread invasive seeds in your landscape.
So, your husband was right, Russian Thistle does indeed make tumbleweeds. However, you may feed Nyjer seed without worry.
The birds and I thank you for your interest in feeding wild birds.