Gravel and weeds got you down? No longer! Try Riverbank Lupine today!
From its name, you might think riverbank lupine likes the moist, rich soil that you sometimes find on the sides of rivers and streams. At least, that's what we thought when we first heard the name. But this plant actually likes those gravelly, sandy, dry areas that you find on sandbars, beaches, and former construction sites.
How does it thrive in these places, where few other plants can live? Lupines are a member of Fabaceae, or the legume family. Like many legumes, they host nitrogen-fixing bacteria in their root system. If you pull a legume out of the ground, you'll see lots of clumpy nodules along the roots - that's where the bacteria live. These bacteria take nitrogen and convert it into a plant-usable form, which the lupine then uses. One benefit of this is that after the lupine dies, the nitrogen is left around for other plants to use. So the lupine both thrives in the gravelly soil, and conditions the soil for future plants.
Riverbank lupine grows fast, and is good at outcompeting weeds.
Photo Credit: "Lupinus rivularis" by space_coyote is licensed under CC BY 4.0.