Wednesday, February 17, 2010

Weeds

By Nina Berryman

In Nicole’s last article she mentioned the difficulty of staying on top of weeds, especially in August. Ms. McAtamney, the AgroEcology teacher at Saul, stopped by the farm today and said, “your article made it sound like it was terrible down here, but everything looks fine!” In co-managing a farm for the first time this year, I am realizing that you are always your own harshest critic. I’ll walk around the farm and feel a wave of anxiety come over me as I see a lawn of grass where there should be cultivated soil, or when I watch a dusting of spiny amaranth seed float away in the wind. Then I’ll stop by one of the other Weavers Way farms and glance over the beds without a critical eye and see nothing but beautiful, orderly rows of vegetables. However, in recent conversations with my coworkers, we have laughed and comforted ourselves in the fact that every farm any of us have ever worked at has had to look for their onions beneath a field of weeds. We told ourselves that we should give ourselves a break when anxiety levels rise as we look at our own field of grass where our leeks are supposed to be thriving.

Every farmer’s approach towards weeds is different. Some people are perfectionists and spend all their time pulling every last weed. Others embrace what nature has to offer and welcome weeds as an unplanned source of food, a key to soil nutrient imbalances, or even a ground cover that they didn’t have to put down themselves. Generally speaking, a weed is any plant you don’t desire in your garden or farm. Simply learning more about a specific weed, such as its edibility for instance, can change your perspective on its desirability and perhaps even promote it out of anxiety-causing weed status. Here are a few common “weeds” that are actually quite tasty and nutritious:
• Purslane (Portulace oleracea)- great eaten fresh in salads, has a watery, slightly citrus flavor
• Lamb’s quarters (Chenopodium album) -similar to spinach, eat raw or cook lightly
• Chickweed (Stellaria media)- a mild, refreshing taste, eaten raw, crush the fresh leaves to help heal a skin irritation or insect bite
• Wood Sorrel (Oxalis species)- citrus tasting leaves, eat fresh
• Dandelion (Taraxacum officinale)- eat the leaves fresh, has a bitter taste

It’s no wonder weeds occupy so much of a farmer’s time and concern: one cubic foot of soil can contain as many as 7,000 viable seeds! With such numbers, it seems wise to capitalize on their multiple functions, if possible. In addition to serving as a source of food, some weed varieties can serve as a type of living mulch. A living mulch is a mulch that is growing in the ground underneath the crops. Clover is often used as a living mulch. Chickweed is one of the best living mulches I have ever worked used. Of course, it is no simple task to get chickweed to grow in the places you want it to and not in the places you don’t!

Weeds reproduce in two ways- either by division or by seed. You might be familiar with the term “division” in reference to dividing a perennial flower. The same concept applies- you take the roots, you break them apart, now you have more plants! This is unfortunately what happens when we are weeding grass with long rhizomes (a type of root). It is nearly impossible to remove the entire root structure and we inevitably leave some in the bed which will then re-sprout in a few days. Reproduction by seed happens when a dandelion goes to seed and releases its white dander into the wind. These seeds can land in the soil and either sprout right away, or become buried and remain dormant in the soil for years and years. Cultivating the soil brings many of these dormant seeds to the surface, exposing them to light and causing them to germinate. Because of this process weeds are known as the primary succession of vegetative growth after a disturbance. Herein lies on of the main arguments for not tilling the land, a method called no-till farming.

For those of you who are interested in neither embracing the weeds and letting them grow, nor weeding by hand for fear of leaving roots in the ground, nor cultivating the soil for fear of encouraging the germination of weed seed, there is another option- smothering! This the traditional mulching technique of layering a thick layer of leaves, wood chips, cardboard or anything else to suppress the weeds. The word “mulch” comes from the German word meaning “soft,” however not all mulches need to be soft. Small pebbles are a popular much in landscaping. We are experimenting with using burlap coffee bags in one of our pathways. Some people do a combination approach of pulling out weeds by hand and then laying them back on the bed to act as a mulch. This approach only really works if you have weeds that do not re-root easily.

At Henry Got Crops! we use primarily the “pull out as much as you can as fast as you can” method. 99% of our weeds are perennial grass. This is because up until this spring that whole area was maintained as lawn. I think I am not alone in saying that perennial grasses are one of the worst weeds! Their root systems are extremely extensive, aggressive and resilient. Plus, they also produce seeds rather quickly, so we are combating them both from above and below! If we had more mulch supplies, such as leaves or cardboard or burlap bags I would like to do much more mulching at the farm as opposed to the hand-weeding and tilling we primarily do. I would also like to experiment more with living mulches, although I would probably seed clover instead of waiting for chickweed to pop up in the right places! We experimented with seeding clover as a living mulch in one bed of broccoli this year. However it didn’t germinate well (perhaps not enough sun) and soon the grass took over.

If any of you have weeding techniques or stories to share, we’d love to hear them!

Sources:
Coleman, Elliot. The New Organic Grower. Camden East, ON. Old Bridge Press, 1989

Storl, Wolf D. Culture and Horticulture. Wyoming, RI: Biodynamic Literature, 1979.
Dawson, Adele. Herbs, Partners in Life. Healing Arts Press, Rochester, Vermont. 2000.

Newcomb, Lawrence. Newcomb’s Wildflower Guide. Little, Brown and Company, New York. 1977.

1 comment:

  1. I agree that grass is an evil weed! I started my garden beds on previous sod. The grass is persistent as anything. Dumping compost and wood chips on top of the garden has killed probably 80-90% of the grass but it still encroaches from the edges. My next step is going to be putting a barrier around the garden to prevent them from moving in from the outside. :)

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