Disease Control For Microgreens

by RightFit Gardens | Last Updated: May 15, 2021

Most microgreens can be harvested in a matter of days instead of weeks when they have germinated well. They proceed to restaurants, farmers’ markets, and retail outlets shortly after harvest, as they have such a narrow shelf life as a food product. As a superfood, microgreens have been renowned for giving an energy boost despite their tiny appearance.

Several things can go wrong, causing you to veer off course. Pregnant women, the elderly, children, and those with weakened immune systems are at risk of serious illnesses, life-threatening infections, and other complications when consuming raw food. Follow these tips to make sure you get fresh produce most of the time.

Mighty Little Greens

microgreen disease controlThe University of Illinois describes microgreens as seedlings that have produced their first true leaf. Microgreens have been popular with farmers and consumers for several years now. Several reasons explain why the demand for microgreens instead of leafy vegetables had increased since 2006 when they became a significant trend in haute cuisine. One reason is their ability to reduce the risk of chronic disease by ensuring that you’re getting sufficient cups of vegetables in your diet. Their antioxidant content and carotenoid concentration enhance their nutritional quality. You can lower your LDL cholesterol and triacylglycerol levels and reduce the risk of cardiovascular disease by eating red cabbage microgreens, for example.

Varieties of microgreens are used in soups, salads, garnishes, smoothies and are served both homemade and in restaurants by health-conscious consumers and chefs. They contain bioactive components such as phytonutrients and plant metabolites, which are valuable in diet-based disease prevention or more robust immune systems. Typically, because the shelf life of microgreens is short, they aren’t grown on a large scale or shipped across the country on a large scale but instead are sold directly to local markets, offering an opportunity for small growers.

They tend to grow faster in warm climates than they do in cold states to grow year-round in greenhouses. They can also be grown year-round in cold frames and greenhouses in warmer regions. The profits are pretty good too. Microgreens cost about 25 cents to produce and sell for about a dollar each – costing more than mature greens or their mature counterparts. Growers should expect to make 25 to 25 cents a square foot selling microgreens.

Management Of Microgreen Pests and Diseases

Phytophthora and Pythium are the most severe threats microgreens face. Beet microgreens can suffer from damping off. However, this can be due to two cultural factors: too dense seed spacing in their flats and insufficient air circulation.

When growing microorganisms, the best practice is to keep microgreens cool and humid, pick the right kind of growing medium, and space them appropriately. Due to their short growing cycle, they do not require any pesticide treatment from the start. To increase the phytochemical concentrations and carotenoid content of these greens, the light intensity and light quality of the light source plays an important role.

As grown without potting soil or a layer of soil, we might not experience common diseases other growers encounter. Most microgreen varieties are in the system for too short a period to be afflicted with disease, as is our experience. These delicate greens come in a variety of varieties, and some are thinner and softer than others. Some of the varieties that come to mind from experience are watercress, Swiss chard, Thai basil, mint, and nasturtium.

Other pests and diseases may exist, but these are among those we have experienced problems with, namely whiteflies and aphids. Infections are less common than pests. The fact that seeds are subject to mildew is a significant factor affecting the risk of disease. That is why they should be sterilized. The use of commercial and homemade seed treatments can prevent mildew on grasses and protect against pathogen growth that can harm the greens themselves. Microgreens should be washed with water and dried with paper towels or a salad spinner before serving.

Microgreens’ Growth According To Difficulty

Microgreens can be grown from salad greens, leafy vegetables, herbs, or even edible flowers, though some are more suited to germinate. The following microgreens are easy to grow and are fast and easy to harvest: arugula, radish sprouts, broccoli microgreens, mustard, broccoli rabe, bok choy, and other Asian greens, cress, lettuces.

Here are some microgreen species with more challenging growing requirements: amaranth, beet, Swiss chard, cilantro, basil, dill, carrots, peas, and purslane.

The organic treatment includes various products like peroxyacetic acid mixtures, which microgreen growers widely use. A less expensive alternative is to mix four teaspoons of white vinegar with four teaspoons of food-grade hydrogen peroxide and soak seeds for 10 minutes.

It is recommended to soak larger seeds like peas for an extra eight hours due to their larger size. You can also soak smaller seeds for a shorter period as a preventive measure but a shorter period overall. One way to inhibit the growth of spoilage of baby greens is to purchase high-quality seed that has been tested for fecal contamination.

When you grow commercially, you will test your conventional seed options beforehand to reduce the chances of microbial growth. It is unnecessary to test for a disease, but it is worthwhile to treat the seed beforehand or inquire about seed lot testing from the seed company. Not every grower does this. We prefer a little peace of mind.

Plants are grown without a layer of soil with a peat-based potting medium instead of hydroponically, about 50-50. Commercial greenhouse growers tend to use hydroponics more than soil-less media growers. If you have a sizeable automated greenhouse, you are likely using hydroponic systems. Small direct-market farms most likely use soil-less media for leafy green vegetables.

The use of sterile medium and clean water will go a long way in preventing many diseases present in raw food, such as rocket microgreens. We discourage using untreated surface water from ponds and other sources to water these delicate greens because of the risk of disease and contaminated produce.


What are the microgreen postharvest concerns?

Several preharvest practices affect the postharvest nutrition profile, food safety, shelf life, and the quality of broccoli microgreens. Microgreens share many characteristics with sprouts, and while they have not been associated with any foodborne illness outbreaks, they have recently been the subject of seven recalls.

What are the sources of foodborne illness?

Fruits, vegetables, meats, and just about all fresh produce can pick up harmful bacteria from many sources, from contaminated soil and water to your contaminated cutting board.

What are the signs of getting sick from eating contaminated food?

The signs of getting sick from eating contaminated food include vomiting, diarrhea, abdominal pain, and flu-like symptoms, such as fever, headache, and body ache.