By Stephanie Hudak, Columnist
As I was planting pansies at Heritage Hall last week and digging through some crunchy soil (where is the rain when you need it) — lo and behold I unearthed some worms. Realizing that I hadn’t seen many worms lately I took the time to really “look” at them – ick on the touching part.
Being an integral part of our gardening life, I did some research and thought you might appreciate reading some interesting facts about our underground friends. Not surprisingly, there are thousands of different earthworm species around the world with a wide range of size, color, feeding habits and burrowing behavior.
Focusing on their dwelling habits will help in understanding how they affect our soil and plants. Earthworms that live and feed at the surface and under the litter layer are called epigeic (epi = top; geic = earth) worms and rarely burrow deeply into the soil.
They are small bodied with a red-brown pigment which helps protect them from UV rays. The endogeic (in or internal) worms lack pigmentation but may appear gray, pink or whitish. By their nature they live and feed in the mineral soil layers, where they ingest/digest the organic material found there.
The deep burrowing species (anecic) are large worms, up to 24 – 45 inches long (OMG), and have a reddish-brown color. They form vertical, unbranching burrows down to six feet but feed on surface litter which they pull down into the burrows.
There is only one species of anecic earthworm – the common night crawler. They eat huge amounts of litter each year and can have a negative effect on the forest floor….more on that further on. Worms have no arms, legs, eyes or teeth.
The eating part is done by pulling food into their mouth with their prostomium (a tongue-like lobe), storing it in the crop, then ground up into digestible pieces in the gizzard where the nutrients are absorbed into the body.
They will eat all sorts of dead and decaying things and can produce their own weight in castings (worm dung) every 24 hours. They don’t need to see, but can sense light, especially at their front end. But they will move away from light – and will become paralyzed if exposed to light for too long, about one hour, so don’t leave them on the surface if you dig them up. Without protection from the sun they will eventually die.
Now here come the fun facts. Over half a million earthworms can live in just one acre of soil (I should be so lucky). Combined they can eat nine tons of leaves, stems and dead roots a year. Besides turning over more than 36 tons of soil they bring subsoil closer to the surface, mixing it with topsoil. Another benefit is the slime they secrete (yum) which contains nitrogen, a key nutrient for plants.
The slime also helps to hold clusters of soil particles together called aggregates, allowing air and water to penetrate the ground. Worms are hermaphrodites, which means they contain both male and female organs. Mating is done by joining their clitella (I’m going to let you look that one up yourself) and exchanging sperm.
Egg capsules are formed inside the clitellum — the band that is located near the head of the worm; and babies are not born – they hatch from cocoons smaller than a grain of rice. Did you know that Charles Darwin studied worms for over 39 years!!
There must be a lot more to worms than we imagined or Charles was a slow learner – I’m thinkin’ it was the first part. And one last bit of trivia – it is not true that if you cut a worm in half you will get two worms. If you cut (accidentally I hope) a worm near its tail it will regrow another one. Anywhere else and you’ll get a dead worm. Besides the dinosaurs that became extinct, native (America) earthworms almost became just a blip on the history map due to the last ice age when glaciers scraped the earth clean.
The ones that survived were only in areas that did not experience these glaciers. Many of the earthworms we find now are non-natives which were introduced by European settlers, either in the root balls of their transported plants or by intention since they knew how valuable worms were to the ecosystem.
There are two basic classes of ecosystems in connection with worms. In manmade environments like farms and gardens, worms are helpful as soil aerators. But in natural habitats, such as hardwood forests, they were “earthworm free” by design. Those forests relied on tiny fungi and bacteria to do the recycling tasks — slowly.
Earthworms recycle wastes faster which causes the soil to drop away from the tree roots, a sort of “tree root gingivitis”, resulting in the trees’ early death. The invasion of non-native worms is worthy of its own story, but I think you have digested enough about these lowly but valuable critters for now.
The next time you are digging in the soil and come across some worms, give them the respect they deserve for all the good they are doing for your plants. I like ‘em more now but I’m still not going to pick them up!! Hey, another Christmas idea for you.
My friend Jeff Johnson – you remember him, the master gardener, certified composter and earthworm savvy guy — showed me a tool called “Silky Pocketboy 130”. It is the neatest folding small saw ever. It comes in three blade sizes: fine, medium and coarse. Perfect for pockets, backpacks and garden buckets.
Amazon has all three. For books: I just got my copy of Chinese Medicine in Everyday Life by Gail Reichstein. It is a practical introduction to the “physical, emotional and spiritual forces at work in our lives….provides a vital contribution to the field of mind-body medicine”. Enjoy raking those leaves on these awesome fall days, and supersize those hugs – give a group hug.