Why Are My Microgreens Dying? (10 Causes / 10 Solutions)

Microgreens are growing in popularity, and it is easy to see why. Whether you are adding a burst of flavor, a pop of color, or just want the added nutritional benefits, microgreens are a splendid addition to almost any dish.

Those of you who have attempted to grow microgreens will know that these seedlings can be more tricky to grow than one might think. Many beginners will see their microgreens wilt and die, despite their best efforts.

The two most common mistakes made by novice microgreen growers are under-watering your plants or providing them with the incorrect amount of light.

However, there are various other factors that can result in your crop failing to flourish. So let us take a look at the ten most common causes of microgreen mortality.

Incorrect watering

Under-watering is the most common mistake when growing microgreens. Often the plants around the edge of the crop will be the first to dry out and fall over as they receive less water than those in the center.

This is why it is vital to make sure that the water is equally distributed across the entire crop. The soil should be damp and moist but be careful! Too much water and you’ll suffocate your seedlings. Over-watering can also result in other complications such as mold and mildew

Harvesting time

Another key, yet often neglected aspect of growing microgreens is harvesting them at the correct time. If left for even a day or two too long, the plants will begin to fall over and die.

Microgreens have a limited embryonic starch content and are therefore incapable of growing tall without collapsing. The over matured microgreens will have considerably less flavor and color, so it is important to time the harvest correctly.

Seed Quality

Seeds can vary in quality depending on how they are stored and handled. Both the handling and storage of the seeds greatly affect the likelihood of the seed being able to germinate, as well as the speed and overall quality of the germination process.

It is important to obtain your seeds from a reliable and reputable source, and store them under the correct conditions. It is also recommended to pre-soak the seeds eight to twelve hours before sowing them in order to promote the germination process

Seed Quantity

The more seeds that you have, the less water, nutrients, and sunlight available to each seed. Competition for inadequate resources will result in the death of a large proportion of your yield and result in the remaining plants being sub-par in quality.

Each seed needs adequate contact with the soil, as well as the aforementioned resources, for a successful germination process to take place. However, some competition is useful in speeding up the growth process and provide structural support for each other to grow.  As with everything else, it is all about balance.

Temperature

Due to the sheer amount of water needed by microgreens, excessive heat can cause the drying out of the plants and soil, which can decimate your crop. This is especially true if your plants aren’t yet acclimatized to the heat.

The ideal temperature to grow microgreens is at 70 degrees F (21 degrees C), so try to keep the temperature close to this. It would also be worthwhile storing your plants in a greenhouse, shade, or slightly humid area to slow the rate of water evaporation due to heat. Needless to say, it probably wouldn’t be wise to leave them outside on a hot summer’s day.

Ventilation

On the other hand, too much humidity can suffocate the plants (and roots) from receiving sufficient oxygen. It also stops plants from being able to transpire and gain nutrients from the soil.

Always remember to keep the air moving, especially in extremely humid environments like those of a greenhouse. The circulation of air can also be used to maintain the ideal temperature necessary for the microgreens to thrive..

Water pressure

Microgreens have a shallow and underdeveloped root system. Therefore, even a slight amount of water pressure can cause them the be uprooted or fall over. The plants will also begin to wilt due to the excessive water pressure.

It is best to water your microgreens using sub-irrigation from below the soil, or a fine mist from above. A wide-headed watering can may suffice, but try to stick to using mist if possible.

Damping off

Damping off is a disease that affects a wide variety of flowers and vegetables, but it is extremely prevalent in seedlings. It is caused by fungus and mold which can be transferred to the microgreens via the water, soil, equipment, or even by air.

The symptoms can vary depending on which part of the plant is infected. Usually, the leaves will become waterlogged, withered and translucent. The stems will grow thin, dark and floppy. And if the disease is in the roots, the plant may not even grow at all.

Once your crop has damping off, it would probably be best to throw out the batch and start again.

Tall, thin stems

Different types of microgreens grow differently. The most challenging ones to grow are those with long, thin stems (such as chives or amaranth). These long stems are especially flimsy and can collapse under even the slightest pressure.

Various environmental factors can cause tall, flimsy, fragile stems. The usual culprit is insufficient light exposure, so make sure your plants get just the right amount of light.

Disease and Hygiene

Molds, fungi, and other dangerous microorganisms put your vulnerable plants at constant risk. It is very difficult to get rid of a disease, such as damping off, once it has infected your crop.

The only way to deal with diseases is to control the environment in order to prevent them from coming into contact with your plants in the first place.

Keeping your equipment sterilized, using clean soil and water, sowing the seeds correctly, not sowing too many seeds, and creating the ideal environment for your microgreens to thrive, are some ways in which to prevent diseases from attacking your precious plants.