Fruit and Vegetable News

Marissa Schuh A hot weekend shifted into a week of wildfire smoke over much of the state. Some areas got some soaking earlier this week, and there is some more rain in a forecast, a relief as much of greater Minnesota is abnormally dry or in D1 drought . Some beautiful early season produce is being harvested and heading to markets and CSA boxes. Wildfire smoke and plant health The effects of wildfire smoke on plants is poorly understood, and what we do understand is that it is complex. For example, while the smoke does block some sunlight, it also creates diffuse light, which can more easily penetrate the plant canopy than direct sunlight. If the smoke is high in ozone, this can damage plants, causing a variety of white and yellowing speckling on a wide range of vegetable crops. The impact of the smoke will also vary depending on how close or far you are from the source , we may see different things in parts of Northern Minnesota where there were local fires, compared to the metro and...

Madeline Wimmer, UMN Extension Educator- Fruit Production & Soon Li Teh, Extension Specialist and Assistant Professor in Grape Breeding and Enology Image: a plant nutritional pyramid showing from bottom to top those nutrients supplied by air and water: Carbon (C), Hydrogen (H), and Oxygen (O); primary macronutrients: Nitrogen (N), Phosphorous (P), and Potassium (K); secondary macronutrients: Calcium (Ca), Magnesium (Mg), and Sulfur (S); micronutrients: Molybdenum (Mo), Boron (B), Nickel (Ni), Copper (Cu), Zinc (Zn), Iron (Fe), Chlorine (Cl), and Manganese (Mn).  Graphic created by Madeline Wimmer, 2023. Plant nutritional analysis—also known as foliar/leaf/petiole testing—is the practice of analyzing nutrition within a plant to determine adequate, excess, or deficient nutrient levels. Oftentimes, this involves collecting a plant’s leaf, leaf with petiole, or only the petiole at a specific growth stage.  Plant nutritional analysis is a critical step in determining any poten...

Marissa Schuh, Horticulture IPM Extension Educator. Originally published in 2023, updated 2025. Flea beetle continues to be one of the biggest pests on Minnesota vegetables farms, especially in our brassica crops. Some of the most effective things we can do to manage this pest happen before we see damage (AKA, the combination of rotation and row covers).  We're past the window where that particular tact can be taken, as applying row covers where flea beetles are already feeding just keeps them close to our crops. Flea beetle damage on mustards. Whitney Cranshaw, Colorado State University, Bugwood.org Quick refresher on some key things that can be done about flea beetle at this point in the growing season. The larger the crops are, the more resistant they are to feeding (though they do often feed on what we are hoping to sell). Solanaceous crops may be getting to the point where flea beetle feeding matters less. Kaolin clay can provide a physical barrier to feeding (but doesn’t alw...

Marissa Schuh, Horticulture Integrated Pest Management extension educator Thinking about scaling up your vegetable production? Curious about irrigation setups, integrating chickens into a vegetable farm, or organic pest management? Want to connect with UMN researchers and extension educators? Sign up now to attend the Organic Fruit and Vegetable Field Day July 15 from 5-8 on the UMN St. Paul campus . Enjoy a free meal, tour university research plots, and network with other growers and resource people from the UMN. This event is free and will be interpreted, please register so we can make sure we have enough food and the right interpreters in place. This event is sponsored by the Midwest Transition to Organic Partnership Program. For more information and registration, visit the event information page  or fill out the below form. Loading… Questions? Reach out to Marissa Schuh at mschuh@umn.edu.

Annalisa Hultberg, Extension Educator, food safety This time of year we get calls and emails from growers thinking about their markets and expanding opportunities this coming season. You may have heard about a GAP audit, and wonder what it is and how it could benefit your operation.  Here are 5 key things to think about if you are considering a GAP audit. What is a GAP audit?  A GAP audit is basically a verification that your farm is following science-based best practices for food safety in growing fresh produce. An auditor from the Minnesota Department of Agriculture (MDA) or another certifying body comes to your farm with a checklist to verify that you use Good Agricultural Practices during the growing, harvesting, packing, storage, and transportation of your product. It is not a law or regulation; it is a voluntary audit that you pay for, and farmers generally get it to access a market that requires an audit.   Read more about what the audit is and who needs it: 1...

Cool temperatures have made for comfortable planting weather, but we’ve seen quite a few cold stressed plants this week. The week ahead looks ideal for planting: warmer, drier weather means it’s time to plant all of our warm-season vegetables outdoors. This week you’ll want to keep an eye on: cutworms, high tunnel humidity, and preventing plant damage when using landscape fabric and plastic mulch. Cold stressed plants Heat-loving plants like cucumbers, sweet potatoes, bail, and peppers can experience significant cold stress when they’re moved outside, even if temperatures don’t technically reach freezing. While it can be tempting to start planting in early to mid May when the weather is warm and sunny, we so often have a cold snap towards the end of May that it’s usually worth waiting until early June to plant our heat-loving veggies. The basil and sweet potatoes in the photos below show classic signs of cold damage. They will likely survive, but they are starting the season at a disad...