Being grateful for weeds is tough. So much psychological research tells us that cultivating gratefulness leads to a more peaceful, healthier life. But grateful for weeds?
Gratefulness wasn’t my immediate response when I saw how weeds invaded my newly planted strawberries while I was gone. The new strawberry beds were totally free of weeds when I left. I didn’t think of them at all for three weeks in Africa. Now they are totally infested. The weeds have done what they always do in resilient agroecosystems: cover the ground I’d left bare. They cover the soil–stopping erosion and adding organic matter. If weeds don’t cover your bare ground, you have real problems. Rains may have failed or the soil may be just too rocky or poisoned. So be grateful for weeds, they mean resilience.
I just finished cleaning out the strawberry beds as the thunderstorm moved in. Its been wet here so the crab grass and its friends pulled out of the ground easily. A sunny day would have helped my weeding. Weeds pulled up and tossed into the sun will die. In our rich Delta soils, lack of sun means weed pulled out and left on the surface often roots again, especially if it rains soon after. Our rich soils also mean our weeds aren’t quite so vicious.
Rocky soils generate much meaner weeds. At Meadowcreek, we get invaded by all kinds of weeds with thorns and stickers. In one bottom, the locust trees, thistle, and even prickly pear cactus have taken over. It’s been overgrazed and neglected for 20 years. When the cactus blooms in the Spring, the yellow flowers are spectacular. Until we get the time and resources to clean up this field, we’ll just enjoy those flowers.
In newly cleared areas on the slopes–such as above our new pond, blackberry, greenbrier and Canada thistle are the main problems. Just as in the infertile soils in the bottom, all these species have thorns.
Why do the weeds which infest stony, infertile soils so often have thorns? Weeds in infertile conditions need more protection to do their jobs. Since fewer plants can survive the infertile conditions, they get gobbled up by deer and other herbivores. Only the ones with a solid defense survive.
In really dry, infertile soils the defenses of plants are much worse than just thorns. .
.In hot, dry, infertile Australia, the Gympie-Gympie is a poisonous plant covered in tiny hairs. In contact with human skin, these hairs deliver a string that can remain blindingly painful for up to several months — or, if you’re unlucky, over a year. One scientist (who was wearing welding gloves when she got stung) compared the sensation to “being burnt with hot acid and electrocuted at the same time.” There’s lots of folklore centered around the Gympie-Gympie, such as horses jumping off cliffs because of the pain the plant inflicted on them. There’s even a story of a World War II officer committing suicide after mistakenly using the tree’s leaves as toilet paper. Seeds of gympie-gympie germinate in full sunlight after soil disturbance. Their poison insures they won’t be eaten or pulled up and the ground stays covered.
It doesn’t necessarily take infertile soil for noxious plants to thrive. Stinging nettle and poison ivy love deep rich soils in creek valleys. Luckily jewelweed usually grows close by and its juice counteracts the sting of the nettle and the itch of poison ivy.
Other plants produce chemicals which have little effect on animals, but kill other plants.
You know about white pine privilege, right? Pines are like people. They make it easier for other pines to survive. They lay down a lot of acidic needles which acidify the soil and make it way difficult for oaks and hickories to survive near them. Azaleas and blueberries do fine cause they like high pH soils. Pines make the world better for pines.
So we can call these plants evil, but all that really means is that we don’t like them. To be either evil or good, something has to have a purpose, doesn’t it? And plants don’t have a purpose. They just are. They are the way they are because of a unique history their species has had in adjusting, adapting and innovating in response to all the other species around them and to their physical environment. Just as all the other species are similarly adapting and innovating. It’s coevolution.
Read more about it in Chapter 4 on working with nature and Chapter 5 on complementary diversity in our book at: https://meadowcreekvalley.wordpress.com/projects/land/roots-of-resilience-the-book/