In the middle of the growing season, when container sunflowers on the deck look as beautiful as these, it would be easy to miss a not-so-showy failsafe of Nature.
When we think of a flower’s role in plant longevity, producing seeds come to mind. Then we look for friendly pollinators that help make that happen.
Plants benefit from pollen spread as pollinators get nectar and sometimes pollen for food. Plants go to great lengths to entice the pollinators with their flowers that are easy to spot and easy on which to land. Plants supply sweet nectar and sometimes fragrance too. Plants need to keep beneficial insects around, checking, until the flowers bloom.
Some plants entice pollinators another way. The evidence showed up by accident on a photo of sunflower leaves before sunflower buds even appeared on the plants.
Notice the tiny droplets on some of these leaves. One might think they are dew, that is, water condensing on leaves from the air. It was a chilly, humid morning in early June. The droplets are spaced so evenly along the edge of the leaf, however. If one could taste a droplet, it would reveal that it is more than water. Pores on the sunflower leaves are located here for a reason.
No flower buds had yet appeared on the plants. The liquid secreted from the plant’s xylem is a nutrient-rich food source meant for beneficial insects. “Guttation” is the biological process that gives some plants the ability to reward bees and other pollinators that check on the plant as the season progresses, even before first bloom. It’s a source of food for insects before plants bloom.
It so happens that sunflowers bloom a little later in the summer. Another common plant on which one can see the tiny droplets is cucumber leaves.
If you want to read more about guttation on blueberry plants, the November/December issue of The American Gardener has an article.