Growing Black Oil Sunflowers

Helianthus annuus

With the pounds of black oil sunflower seeds that were loaded into my birdfeeders over the winter, I suppose it was inevitable that some would fall into the planters on my deck and germinate. I set aside one of these planters this year for the black oil sunflowers. Now they’re up and blooming! They don’t seem to vary much from this basic design. And they don’t look very different from the mammoth greys that I grew last summer.

Black oil sunflower seeds are also the kind used for pressing sunflower oil. They seem to be a favorite of the birds around here, disappearing from the feeders before any other variety.

There’s evidence that black oil sunflower seeds have some allelopathic qualities – that is, they discourage growth of some of the other plants around them because of chemical interactions. Gardeners should be aware of this when using large amounts near areas where special plants are growing. I think I’ll be limiting my planting of these seeds to containers and areas that I want keep clean of weeds.