Learning From a Pro - Weed Control on an Organic Vegetable Farm
By Harriet Behar

This article was first printed in the July 2007 issue of the Organic Broadcaster, published by the Midwest Organic and Sustainable Education Service.

While weed control requires a lot of attention on any type of organic farm, vegetables offer a wider variety of challenges, since most vegetable farms grow a wide variety of vegetables!  Onions need different management than carrots or lettuce or beets or potatoes or melons or tomatoes (you get my point).  Steve Pincus of TIPI Produce in Evansville, WI has been a vegetable grower for over 25 years in three different farm locations. He and his wife and farm partner Beth Kazmar shared their vast experience with a group of over 25 people who attended a CRAFT (Collaborative Regional Alliance for Farmer Training - http://www.csalearningcenter.org) field day at Angelic Organics on Saturday June 9th, 2007.

Steve has been a regular vendor at the Dane County Farmers Market for many years, although in recent years he has switched his focus to a CSA and wholesale accounts.  He has planned his crops this year to fill the 300 CSA boxes, which require a wide selection for at least 26 weeks during the season with some storage crops offered as well.  A variety of large plantings of one crop are done to fill wholesale markets such as Whole Foods Market and Outpost Natural Food Co-op in Milwaukee.  Management is a big part of any diverse vegetable farm, with thought given to crop rotation, building soil organic matter, fertility, slope, drainage and weed seed bank when planning where to plant each crop each year.  Steve stated that after 18 years of continuous conventional corn, the land on this farm was finally “coming around to health” since their 6+ years of organic management.  Each soil type also has its own challenges, with Steve’s experience including clay, clay loam, silt loam and now a sandy loam on his current farm.

The terrain on this south central Wisconsin farm is flat to slightly sloping, with a subsoil of sand.   This allows TIPI produce to get into the fields a little earlier in the spring and after a rain event.  Steve and Beth stressed that cover crop incorporation is an important aspect of their weed management, giving them the soil tilth and biological vitality they need to grow healthy crops and have effective cultivation.  When the soil crumbles and flows nicely during cultivation, there is better coverage of the small weeds and fewer clods are thrown to crush the crop.  Rye and vetch are planted on most of the farm for winter cover, except where the late season brassicas are planted.  This year, they let a portion of the rye and vetch grow tall, and had just mowed it in early June, leaving a bright mat of yellow rye straw.  They planned to plant late zucchini plants into this mulch, and it appeared that they had mowed sufficiently mature rye and vetch so it would not regrow.  Hopefully, the reflective nature of the straw might also disorient the cucumber beetles, similar to a silver plastic mulch.  Every year there is something new to try and something else to learn.

Steve started out by explaining that he tries NOT to use his rotovator, and prefers to use his chisel plow or his Perfecta field cultivator trailed by a set of rolling baskets and a cultipacker roller when preparing his seed bed.  By avoiding the rotovator, he preserves soil structure and has less compaction later in the season, making cultivation easier, among other benefits.

Steve had a wide variety of mostly used or modified equipment to aid him in controlling both broadleaves and grasses.  A leely weeder is run right over the row on transplanted brassicas, onions, and leeks as well as young seed-planted carrots, lettuce, spinach, peas and corn.  This three point mounted equipment can be adjusted for depth, at the same time varying the speed of the tractor to suit the situation. A flame weeder is used to destroy young weeds both pre-emergence of the crop and post emergence. It had recently been used on the asparagus bed, before letting the fronds grow for the summer. Steve showed us his Farmall Super C, setup for two-row cultivation, and stressed the importance of keeping the shovel blades sharp and in good condition.  Having a wide variety of shovel blades, some that dig deep, others that just skim under the surface of soil cutting the stem from the root, provides more tools to deal with whatever the situation. 

Steve attended an auction on a muck farm a few years ago and obtained some unique equipment, including a cultivator similar to an Allis G and a 50+ year old “walking tractor” that used spring harrow shovels instead of a tine-type rototiller.  This is very handy for cleaning up narrow or small areas of weeds between rows.  We all learned the lesson of keeping your eyes open for good deals on useful items.

Weed control equipment is not confined to machinery. Steve showed us a large pile of Japanese short handle hand hoes with very sharp blades, as well as his long handled hoes, more than enough for everyone on his crew.  He has extras so he can sharpen them up ahead of time and no one will need to use a dull hoe.  Black plastic mulch is also used, especially for melons.

After three hours of walking the 40 acres, we returned for a potluck and were delighted this CRAFT sponsored field day occurred during strawberry season!  Thanks to the folks at CRAFT and to Steve and Beth for this informational and inspirational day.

Harriet Behar is the MOSES Outreach Specialist. She was an organic inspector and inspector trainer for many years and has an organic bedding plant and vegetable operation with her husband in Southwest WI.