In recent years, microgreens have become a popular choice for small-scale farmers for its ease of growing and fast turnaround. (1) Best of all, it doesn’t look like microgreens are going anywhere, as customers love them, too.
“[…] quick-growing, high-yield crops such as microgreens […] boost wholesale revenue”
When it comes to your microgreen setup, however, it can be difficult to parse what equipment you need. Do you need trays with holes for microgreens? What benefit does it provide, and can’t you just stick with solid trays?
Do You Need Trays with Holes for Microgreens?
Yes, you typically need two trays for your microgreens growing setup. One tray will have holes, while the other will be solid. This keeps the roots from touching water directly, minimizing the risk of root rot and other problems.
If you want to opt for a hydroponics setup, you don’t necessarily need a tray with holes. Some people prefer to keep the two-tray setup, instead using a mesh tray to provide their microgreens’ roots with structural support.
Is It Better to Grow Microgreens in Soil or Water?
There’s no definite answer on this, though a lot of places will lead you to believe that soil- or soil-like mediums are best.
Hydroponic growing allows you to opt for a different medium with strict control over the nutrients that the plants receive. It is often cheaper as well, since you don’t have to keep replacing spent soil. This becomes the main draw for a lot of people.
A lot of people will argue that microgreens grown in soil do taste better, however, as the plants grow uniformly. Many microgreens growers also swear by soil and soil-less mediums (like coco coir) for improving tray yields.
Challenges of Growing Microgreens in a Single Tray
If you grow microgreens in a single tray without holes, you’re likely to run into a few challenges. First, you’ll find that watering becomes difficult, as the water can damage the newly sprouted plants.
It may also be difficult to ensure the whole tray is getting water, rather than the soil soaking up water in only one part of the tray. In areas of the tray that receive too much water, you’ll start to struggle with mold and root rot problems; especially with longer-growing microgreens varieties.
In most cases, you get a higher yield per tray and must deal with fewer difficulties by growing with a double-tray setup.
How to Use Microgreens Growing Trays
When working with microgreens, it’s often better to reserve the no-holes tray for the bottom layer, with a tray with holes over the top of this. Stacking the trays in this manner provides you with a small gap which acts as a water reservoir.
When this bottom tray is filled with water, the soil soaks up the water and can provide moisture to the growing plants. As the microgreens’ roots filter down towards the bottom of the soil, you’ll also find that some dip into this reservoir as they grow into the hole in search of moisture. This only helps bring the water up to the soil, as the roots actively move water up.
Which Trays are Best for Microgreens?
There are a lot of arguments over which trays are best for microgreens, and ultimately, it’s a personal decision based on your experience. If you don’t want to test out different microgreens trays yourself, then check out this microgreens tray comparison to learn more. Here you can compare features and price and determine which trays are best for your set up, whether you’re a large-scale microgreens farmer, or just want something for your kitchen counter.
Can You Re-Use Microgreen Trays?
Yes, you can re-use microgreens trays, but not the soil. You can use the spent soil or growing medium elsewhere, but the tray must be emptied to re-use it. Once you’ve emptied the trays, you’ll want to wash it to ensure there are no leftover bits of soil or roots clinging to the holes.
If you purchase quality trays (like these trays from Bootstrap Farmer) you can reuse the trays time and time again without any trouble. The main thing that prevents trays from being reused is structural damage that prevents it from being able to hold the soil with a new batch.
How to Sanitize Top and Bottom 1020 Trays
When you sanitize your trays for re-use, you’ll want to make sure that you sanitize them both top and bottom. This includes both the trays that have holes, as well as your water-holding tray without holes. This will ensure that there is no bacterial development that could potentially contaminate the next batch.
Simply wash each tray with soap and water, rinse, and then spray each tray down with a diluted vinegar solution; allow to air dry before re-using the trays. The vinegar solution will help disinfect the surface of the trays.
You’ll also end up with healthier microgreens because they are starting as thriving plants in a sterile environment, rather than plants that must fight against microbes for root support and water. This is particularly important since we are harvesting the plants before they develop their true leaves.
Where to Find Mesh Trays for Microgreens
You can find mesh trays for microgreens at any reputable retailer that sells other flats. A popular choice for 1020 trays with and without holes includes Bootstrap Farmer, who is known for their long-lasting, quality trays and premium customer support. They have a range of 1020 trays and other sizes, with and without holes, as well as a range of mesh options. I’ve had trays from Bootstrap Farmer that I’ve sanitized and reused for going on three and a half years with no breakage or other damage.
If Bootstrap Farmer is sold out, True Leaf Market is a popular choice because they not only offer trays, but also a wide variety of microgreens seeds.
Is Stacking Microgreens Trays Safe?
When you think about stacking trays and pouring water into the mix, you might start getting worried about mold buildup or mildewing over time. So, is stacking microgreens trays safe? Fortunately, yes, it is. With the right set up, you won’t have any trouble with mold.
The primary culprit of mold is above the soil, between the plant stems. If you do not have enough airflow between the stems, then you’ll find that your microgreens struggle and mold begins developing.
Stacking microgreens trays is safe because the water underneath the tray does not sit and fester; the plants roots diligently take up the moisture available to them, drying out the underside of the tray as it does so.
- Forbes, De La Mesa Defies Small-Farm Struggles by Growing Opportunities, https://www.forbes.com/sites/sarahburchard/2019/12/12/de-la-mesa-defies-small-farm-struggles-by-growing-opportunities/?sh=5ca1a5c863f1