How Deep Should Microgreen Trays Be?
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How Deep Should Microgreen Trays Be?
This article is part of our Microgreen Tray Guide, where we explore how tray design affects workflow, soil usage, durability, and long term costs on a microgreens farm.
In the first article, we looked at the hidden costs that trays can create inside a growing system.
In the second article, we measured how long it takes to fill different trays and found that design details can affect daily workflow.
In the third article, we explored why many growers standardise around the 1020 tray size.
Now we are looking at another important detail that is often overlooked: tray depth.
Do Microgreens Need Deep Trays?
In most cases, no.
Microgreens are harvested very young, usually within one to three weeks. During that short growing period, their root systems remain relatively shallow.
Because of this, very deep trays are usually unnecessary for most crops.
Many trays on the market are significantly deeper than microgreens actually require. This means growers often end up using much more soil than needed.
How Tray Depth Affects Soil Usage
Soil is one of the biggest ongoing inputs for many microgreen growers.
When trays are deeper than necessary, each tray requires more soil to fill properly.
That increases several things at once.
- Higher soil costs
- Heavier trays to lift and move
- More time spent filling trays
- More soil to store and transport
Over time these small increases add up, especially when you are filling trays every week.
Harvesting Can Also Become Harder
Deep trays can create another problem that many growers only notice after using them for a while.
If trays are only partially filled out you are using a hydroponic mat, the crop starts lower down inside the walls of the tray.
This can make harvesting more awkward because the stems sit further below the rim, making it harder to cut cleanly across the tray, especially if the tray walls are tall.
Shallower trays allow the crop to sit closer to the rim, which can make harvesting faster and easier.
When Deeper Trays Can Be Useful
Not every crop behaves the same way.
Some varieties, such as sunflower shoots, develop stronger root systems and can benefit from additional soil depth. Although they prefer deeper soil, they grow just fine in shallow trays. Most microgreeners don't find the payoff of using deeper trays and much more soil worth the marginally better sunflower crops and they just grow them in the same trays as everything else.
For growers who produce a large amount of these crops, deeper trays may still be useful in specific situations.
However, for many common microgreens, including radish, broccoli, peas, mustard, and cabbage, shallow trays often provide more than enough soil depth.
Why Many Growers Choose Shallow Trays
Shallow trays are designed with microgreens in mind.
They provide enough depth for healthy root development while avoiding the extra soil volume that deeper trays require.
If you would like to see an example, you can look at these:
Bootstrap Farmer 1020 Shallow Microgreen Trays
Trays like these are designed to reduce soil usage while still fitting standard 1020 systems.
Small Design Details Matter
Tray depth might seem like a small detail at first.
But when you are filling trays, moving trays, watering trays, and harvesting trays every single day, those small details begin to affect the entire workflow.
Choosing the right depth can reduce soil use, lower the weight of each tray, and simplify harvesting.
And just like the other design details we have discussed in this series, those improvements compound over time.
In the next article we will look at another question growers rarely measure directly: how tray design can affect watering time.
Microgreen Tray Guide
- Part 1: The Hidden Cost of Microgreen Trays
- Part 2: Are Heavy Duty Microgreen Trays Worth It? We Timed the Difference
- Part 3: What Size Microgreen Tray Should You Use?
- Part 4: How Deep Should Microgreen Trays Be?
- Part 5: Do Microgreen Trays Affect Watering Time?
- Part 6: How Long Do Microgreen Trays Last?
- Part 7: How to Choose the Best Microgreen Tray System
Microgreen Tray FAQ
Do microgreens need deep trays?
Most microgreens do not require deep trays because they are harvested young and have shallow root systems. Shallow trays usually provide enough soil while reducing weight and soil usage.
Why are some microgreen trays so deep?
Many trays are designed for general horticulture rather than microgreens specifically. Because of this they may be deeper than necessary for short cycle crops like microgreens.
Do shallow trays affect microgreen growth?
For most crops, shallow trays provide enough root space for healthy growth. Many growers use shallow trays specifically to reduce soil use while maintaining good crop performance.