2012 The University of Minnesota Biochar Test Gardens and Challenges (Part 4)


In my last few posts, I’ve described how University of Minnesota Extension Master Gardeners have been involved with the 2012 biochar test gardens with the CenUSA Bioenergy project.  As you’ll see throughout this post, from planting to data collection, we met some challenges with germination, weeds, insects and plant diseases in 2012.

2012- Plans and Design for CenUSA Bioenergy Biochar Test Gardens

What did we decide to grow?

Plants for Biochar Test Gardens
Plants for Biochar Test Gardens

Each site was designed to include basic plants that typical homeowners would grow such as annuals, perennials, vegetables and herbs. The design was laid out with short annual plants in the front and perennials near the back.

Edible crops that were grown included: green beans, tomatoes, green and hot peppers, Swiss chard, leafy kale, cucumbers, lettuce, asparagus, potatoes, and basil.

Ornamental crops included zinnias, petunias, marigolds, MN hardy mums and Ole, Lena and Sven hardy shrub roses.

First Year Test Garden Challenges

Seed and Shade Challenge

Early on we had some germination issues with the beans. Two of the three teams opted to replant, but by the time the second planting germinated, the Swiss chard was so large it shadowed the bean row too much…so no beans.

The potatoes were also spotty. The potato sets were mailed too early from the company we purchased from and even though they were kept under refrigeration, they got moldy and their germination was poor as well.

Pest Challenges: Aster Yellows, Japanese Beetles, and Weeds

Other challenges in the gardens included weeds, Japanese Beetles in two of the tree sites, more weeds, aster yellows disease on marigolds and petunias…and did I mention weeds?

The captioned photograph to the left shows a marigold infected with Aster yellows next to a healthy marigold (however it didn’t stay healthy very long) and embraced by purslane.

Marigold infected by Aster Yellows (yellow arrow), taken over by purlane (orange arrow)
Marigold infected by Aster Yellows (yellow arrow), taken over by purslane (orange arrow)


What to do with Poison Ivy in Andover?

The Andover site as I mentioned, was filled with small trees and underbrush including poison ivy – that also became a challenge to deal with.  However, the Master Gardeners did a great job of keeping it under control by using herbicides only around the exterior perimeter of the garden and hand pulling any sprouts that came up in the garden.

A couple of volunteers were nervous about eating produce that may have poison ivy roots coming into contact with the vegetable roots. Upon researching this concern with the Minnesota Department of Health, they felt the risk was low, but if the poison ivy roots came into contact with root vegetables like the potatoes, it was cautioned to peel the vegetables first.

Poison Ivy
Poison Ivy - A very undesirable weed to have at the Andover test garden


I then went a little further in my research and learned that the famous naturalist, Euell Gibbons, used to recommend eating poison ivy leaves – just a little a day, to build up a tolerance to the urushiol (the toxins in the poison ivy). I then noticed someone had blogged that they tried that and the only side effect they experienced was a little itchiness in their behind after the poison ivy passed through. YIKES!

End of Season Differences in the 2010 Biochar Test Garden

Comparing Lettuce Between Sites – Difficult Since Japanese Beetles Got Dibb

The lettuce, the earliest season crop, was harvested first. However, the Japanese beetles had such voracious appetites in the St. Paul Campus garden that less than 50% of the plants were left to weigh. The Japanese beetles hit the Arboretum site too, but not as badly. Japanese beetles haven’t found Andover yet (which is farther north than the other two sites), but they have been spotted less than six miles from that test site.  I have a feeling we may see them in 2013.

The gardens did get a little over crowded especially in the nutrient rich St. Paul Campus and Arboretum sites. To ease some of that, the Swiss chard was harvested early which allowed for more room for the kale and other vegetables. I will talk a little more about the harvest under “Collecting Data”.

Differences in Garden Vigor?

Overall the gardens at the St. Paul Campus and the Arboretum have the most vigor. It would be safe to guess that is because the soil was so much better, plus the added nitrogen resulted in heavy plant growth. In Andover, there appeared to be a lot of nutrient deficiency, not surprising considering it is very sandy soil and the 10-10-10 fertilizer,applied only once in the spring and had leeched through the soil early in the season.

Interestingly though, there was a noticeable difference on kale size between the control plots and the biochar treated plots. I believe that may be because of the moisture and/or nutrient holding capabilities of biochar in the poorer soils. However, it will be tough to gain analysis between treatment one and treatment two, because treatment two also has morning shade, which also contributes to the moisture not evaporating as quickly, and it also didn’t suffer from heat stress as much as the other two plots.

Collecting Data Will Lead to a More Comprehensive Report Soon!

Zinnias and Swiss Chard growing in Biochar Test Gardens
Zinnias and Swiss Chard Growing in Biochar Test Gardens

Most of the data that we wanted to collect had to do with growth and yields. Weights and counts were collected on produce such as potatoes, cucumbers and tomatoes, plus plant heights, widths, stem strength, bloom production, etc. were also monitored on all of the plants. A comprehensive report with all of the results will be coming soon.

As we prepare for 2013, we are now putting together what we learned from the 2012 growing season so we can improve data collection and improve our research with the  CenUSA Bioenergy project for 2013.

From here on forward, stay tuned, as we begin to blog about our 2013 season as it happens this year!


–Lynne Davenport-Hagen
University of Minnesota Extension
Master Gardener Program Coordinator-Anoka County
CenUSA Biochar Research & Display Garden Project Coordinator-USDA NIFA Grant


“The CenUSA Bioenergy project is supported by Agriculture and Food Research Initiative Competitive Grant No. 2011-68005-30411 from the National Institute of Food and Agriculture.”