Every species of wildflower or native grass has a strategy for making a living: for dispersing seeds or for sprouting from dormant roots. For capturing maximum sunlight to fund plant growth and flower production, for pollination, for pest avoidance, and for a myriad of other life issues they must address. In fact, humans and every other life form on earth must deal with similar issues. We must all–as a species and as individuals—have a way to deal with the threats and opportunities we are presented with. Think of it as a “business plan”.
For instance, vines do not invest in thick, woody trunks to compete with trees for sunlight. They just climb up the thicker stems and trunks of trees and shrubs that have already made that investment, then spread their leaves over the other plant’s leaves to capture the needed sunlight. That is their “business plan” or strategy for competing for limited sunlight.
Or think of bird species that avoid the harsh realities of a North American winter by migrating to milder climes in the tropics of Central and South American. They are like human “snowbirds” who can afford multiple homes to live where the weather is always pleasant. Avoidance is a common theme in the business plans of many organisms.
One strategy that we see in woodland wildflowers is to avoid the stressful conditions of summer by simply going dormant. The photos show a stand of woodland wildflowers in one of our garden beds as they were in late March and again in late July. In the background are Virginia bluebells (Mertensia virginica) that have been blooming for two or three weeks already; in the foreground are Green trillium (Trillium viridescens). In a July photo of the same spot, the bluebells have completely disappeared and the trillium plants are yellow-brown and shriveled. This garden bed is well-drained, being at least three feet above the surrounding landscape, receives no supplemental irrigation, and is dominated by a thick cover of English ivy, a strong competitor. Even still, the bluebells and trillium have thrived in this bed for decades.
As temperatures rise to stressful levels and water competition intensifies between neighboring forbs, shrubs, and trees, these spring ephemerals just check out—dying back above ground, with only minimal moisture needs for the below ground roots and crown.
The ecologist David George Haskell suggests still another important angle to this avoidance strategy in his delightful book, The Forest Unseen—A Year’s Watch in Nature (Penguin Books, 2012). Summer not only brings competition for water and nutrients, but for something even more basic: sunlight.
Spring ephemerals, which appear for only brief periods, emerge often before the overstory trees and shrubs have fully leafed out. Sunlight penetrates to the forest floor for only a limited time in early spring before it is intercepted by the expanding leaves of taller vegetation. These woodland ephemerals, like bluebells and trillium, have a unique business plan: get your leaves out before the big guys do and capture that sunlight; produce your blooms; pollinate; set your seed; store energy to fund this year’s survival and next year’s new growth; and then die back and wait it out.
But other wildflower species actually thrive in the hot, summer months, especially those that grow in open areas where they are not competing with an overstory of leaves for sunlight. Species like those in our Little Bit Shady Wildflower Seed Mix can thrive in either full sun or partial shade.
Next time you become curious about why a plant or animal does what it does, think about it in the context of its larger “business plan”.