Why all this Leaf Litter?
As dawn approaches with leaves turning colors, I ask myself, what do plants think of the coming cold weather? Well, maybe plants don’t actually think, or they do just not in a way we think.
As their leaves change, they slowly fall to the ground. This seems so - end of life. However, they know better. These flowering plants have worked very hard to absorb up the suns energy through their leaves, make flowers to bring in pollinators to help the plant spread their genes and to store nutrients to give back to the soil and composted each autumn. Now the flowering plants take a nap.
Flowering plants at this latitude do this every year; they nap for the winter. But not all plants do this. Evergreen plants, the ancient ones, were here many millennia before flowering plants. They kept their foliage year-round. They would shed some leaves (needles) every 5-7 years and we see that in the autumn when we notice yellow needles on our evergreens. It’s the older foliage that’s tired and needs to drop to the ground and become compost. Some think it must be the evergreen is dying but it’s just shedding old needles. Evergreens, like another ancient plant, ferns, didn’t need pollinators, they spread their pollen on the wind. This is kind of a risky way to pro-create but it worked in an age before pollinators. These early ancient plants had to survive many millions of years of climate changes, moving south when the climate chilled and migrating back north as glaciers retreated. They are survivors.
Flowering plants and insects were kind of late on arrival, developing a different way of pollinating. This was a new evolutionary concept. The ancient plants were thinking, ‘so, what’s so special, our new comers have to spend a lot of energy to make a beautiful flower to bring in pollinators and we just spread our pollen to the wind’. But Mother Nature knew there was a different way. Not giving up the ancient ways but creating a world where both could exist together.
So why do flowering plants drop their leaves? Flowering plants at this latitude do this every year, they shed all their leaves to take a nap. Why change the way the ancient plants distributed pollen? Maybe this was a way of returning some of the energy collected during the summer back to the soil to feed the roots and the microbes that help feed the roots during the seasons; a reciprocal relationship. Roots of flowering plants need the leaf factory collecting sunlight during the summer months and the microbes providing essential nutrients below ground during the growing season and as autumn approaches, leaves drop and their trapped energy liberated by soil microbes. It’s a ‘return on investment’, you feed me and I’ll feed you. Now the energy is stored in the soil and in the coming spring the plants produce more leaves and flowers to collect the suns energy and begin the process for another season. A circle of life.
As the leaves drop in your yard and at our nursery, we are getting ready for this seasonal change. As gardener you all feel the rhythm and know what season is upon us so we prepare for the leaf drop and snow that serve as a blanket protecting the soil biome. As all of these plants and soil communities interact we can only observe. Do plants think? I think yes and maybe when my ashes are spread in the soil, I will learn to understand their language and I will be able to answer that question.