2021 Case Study: Crystal Spring Farm


Crystal Spring Farm, Brunswick, Maine

Crystal Spring Farm is an organic mixed vegetable enterprise operated by Seth Kroeck and Maura Bannon in Brunswick, Maine. The farm consists of 115 acres leased from the Brunswick-Topsham Land Trust, with about 33 acres in tillable land for vegetable production and a majority of the remaining acres in hay. An additional 72 acres are leased from a local family for wild blueberry production.

The farm has been in operation since 2004, and for the majority of that time produced highly diversified vegetables and livestock. However, Seth and Maura stopped raising livestock in 2015, and have since narrowed down production to focus on four vegetable crops and wild blueberries.

Seth has spent the last 25 years farming, with several years in California, New York, and Massachusetts before coming to Maine and managing Crystal Spring Farm.

Challenging weeds:

While Seth indicated that the most abundant weeds on the farm have shifted in recent years, the current main challenge is carpetweed (Mollugo verticillata). Carpetweed has thrived in the understory of carrot crops at Crystal Spring, and has been difficult to remove except by hand-weeding. “The cultivation tools tend to bounce around it, and it survives”, said Seth, which he observes is likely due to a taproot that provides the weed with resistance to shallow cultivation.

Carpetweed shot up in abundance at the farm in 2019, the same year that the farm transitioned from highly mixed vegetables to only a few crops. Since then, Seth suspects that the weed seed has traveled on equipment throughout the farm, and has increased efforts to clean off equipment between fields to reduce future contamination.

Weed management at Crystal Spring Farm:

The first step in weed management for Seth is winter field planning. Knowing the sequence and location of crop rotations is central to his strategy of long-term weed reduction on the farm.

“How I start weed control is thinking about where the cash crop is going to be,” Seth said, “and then once I’ve made that decision, I’m trying to be ahead of the cash crop so I can do a combination of seedbank management and mechanical cultivation.”

Pre-emergence flame-weeding is the main focus of Seth’s seedbank management, while mechanical cultivation includes basket weeders and beet knives for cultivation within the crop row, and blind cultivation with a Perfecta harrow during fallow periods.

Experimental crop and tools:

Tools were tested in fall carrots at Crystal Spring Farm. Seth used the Kult Kress Duo unit with beet knives and HAK tine implements attached to a HAK steerable cultivation unit as the experimental tool treatment, compared to basket weeders as a reference tool.

Stacked tools evaluation:

The amount of possible adjustments with the Kult Kress Duo unit proved to be a challenge in and of itself. Reflecting on his first cultivation with the tool, Seth thought that spending more time adjusting implements could have led to better results, which were not a strong improvement over his typical cultivation methods.

“I think the strength of that tool [Kult Kress Duo] is also a little bit of it’s Achilles, in that because you have so much adjustment, there’s a lot that goes in to getting it just right,” Seth said. “Some of that is just trial and error.”

Reflections from the on-farm research project:

While he may not use the specific tool set-up he used for this project in the future, Seth is interested in pursuing new stacked cultivation methods using tools that he already has or can fabricate at the farm.

“It spurred a lot of creative thinking on my part about how to solve some of the problems that I’m seeing, as opposed to just looking at them. I’m trying to adapt some of the cultivation tools that I have by adding stacked combinations . . . inspiration for that came directly from the project. It’s one thing to go to the trade show and see the tools on the floor, and it’s another thing to see the tools on your farm, see them dragged through, see how parallel linkages work, see what the new European sweep construction looks like, all in your soil. That’s by far the biggest influence - just to kickstart my own thinking about, you know, I have a cultivation system, it works relatively well, I know what the weak points are in it, and this helped me think about those weak points from a different perspective.”

Further information, training, or resources:

Seth would like to see more resources that show how farmers with similar cropping systems in other parts of the country and around the world think about weed management.

“The more linkages we can have as farmers with what other vegetable growers, or whatever group we’re in, are doing in other places in the country and other parts of the world I think is really, really interesting. . . When I’m thinking about new things, I want to know what other people are doing, and what’s their thinking behind that.”

Figure 1: Mental model of the components and connections within the weed management system at Crystal Spring Farm.


  • Gray boxes represent farming system priorities, orange boxes represent overall weed management strategies and goals, blue boxes represent physical weed control practices and decision-making, and purple boxes represent key lessons on using physical weed control tools based on practical experience.

  • Blue arrows indicate a positive relationship and orange arrows indicate a negative relationship between two components.