Experts tackle readers’ garden questions.
Q: We had two new volunteer plants growing last summer in an area where we used to have a bird feeder. The first one is a pretty bush, almost 3 feet tall, with tiny yellow flowers and small leaves. The second plant has interesting leaves and pretty yellow flowers, but the seed pods look like spike balls – nasty! We would appreciate any help in identifying these two plants.
Mary and Fred Meyer, Fair Oaks
Master gardener Fred Hoffman: The ingredients listed on the bag of bird seed used in the feeder should offer some clues regarding the two volunteer plants that have popped up in the yard. However, without knowing exactly which bird seed mix was used, we looked at the most common ingredients found in wild bird seed mixes, according to the Cornell University Lab of Ornithology.
The ingredients may include seeds of one or more of the following: sunflower, safflower, nyjer or thistle, white proso millet, shelled and cracked corn, peanuts, milo or sorghum, golden millet, red millet, flax, rapeseed and canary seed.
The plant “with tiny yellow flowers and small leaves” resembles the plant that sprouts from fallen nyjer seeds. According to the Ventura County Cooperative Extension, nyjer (Guizotia abyssinica) is an annual herb noteworthy for its “oil-producing” seeds.
Apparently, researchers in the United States have looked into nyjer seeds as a potential cooking oil crop, but found them to be less promising than other oil seed crops already under cultivation. This plant poses little threat of becoming a noxious weed if it escapes into wildland areas. Nevertheless, it is an exotic plant not native to California and should not be encouraged to grow and produce seeds.
The plant with the seed pods that look like nasty “spike balls” stumped us. So we turned to Warren Roberts, the superintendent emeritus of the University of California, Davis, Arboretum. Sure enough, Roberts knew the answer, and the plant is not from an ingredient typically listed on a bag of bird seed.
“That’s Solanum rostratum, commonly called buffalobur, a noxious weed,” explained Roberts.
This annual also is not native to California and is extremely toxic to humans and animals, according to Calflora, a nonprofit organization that provides information on plants that grow wild in California. For more information, visit the Calflora website at www.calflora.org.
Fred Hoffman is a UC Cooperative Extension master gardener of Sacramento County.
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