One person’s weed is another person’s wildflower. Some may consider weeds as a vile curse, others may see them as simply a nuisance. How do you see a weed? Typically a weed is best defined as any plant growing in the wrong place which obviously makes for a broad subject to discuss. We try to grow crops, livestock or landscapes for our purposes and these unwanted visitors pop up and free-load from us. Maybe they have something to say.
Weeds are typically categorized as perennials or annuals. The annuals have an amazing ability to pop up in massive numbers under their preferred conditions and outpace the growth rate of ‘desireable crops’. Perennials are more pernicious because they come back from the roots year after year, tangling, choking and smothering what we want to grow. The reflex can be to let the magic genie out of the bottle with herbicide, of course this often results in unintended consequences. Getting a comprehensive understanding of the weeds you’re facing along with their lifecycles and roles in the ecosystem yield more sustainable results.
Many weeds are ‘indicator species’, that is, when they are present they indicate certain conditions such as compaction or nutrient deficiencies. Others are ‘dynamic accumulators’, they have the ability to seek out and accumulate needed nutrients from deep in the ground and bring it back to the active topsoil layer. Still others specialize in covering the ground quickly to protect the soil surface from sun and erosion. In nature, succession is the process of transitioning species from disturbance to climax community. Many weeds are ‘pioneer species’, that is, the first to grow on disturbed ground (like when we plow). As the soil improves, higher quality plants will take root and this process continues until a new disturbance event. Our modern tillage agriculture works against nature so if we cultivate crops, we need to use effective cultural techniques. Moving to perennial polycultures and managed grazing systems is the best way to mimic nature. We can supercede weeds with succession.
Many weeds offer decent forage value but may not be considered choice by our livestock. Increased stocking density with rotational grazing and multiple species of livestock orchestrated through the landscape offers many solutions. Many weeds also offer great value to wildlife. Weeds with toxic or thorny characteristics may need to be addressed with specific techniques. Mowing at specific intervals or during flowering is often effective at keeping many annual weeds to an acceptable threshold population.