Microgreen Trays With Holes vs. Without Holes: What Each One Does

One of the most common beginner questions is why microgreen growers often buy two versions of what looks like the same tray: one with drainage holes and one without them. The answer is simple—the two trays do different jobs.

The tray with holes

The upper tray holds the growing medium, seed and crop. Drainage holes let excess water leave the root zone and allow water to move upward into the medium when you bottom-water.

The solid tray

The lower tray acts as a reservoir and catch tray. It keeps water off the shelf or counter and lets you add water beneath the crop instead of pouring it over the canopy.

Why the pair works well

Nested trays make it easy to switch from surface misting during early germination to bottom watering after roots are established. University of Maryland Extension describes commercial microgreen tray sets using the same basic arrangement: a shallow tray with drainage sitting inside an undrained tray that acts as a water reservoir.

Do you always need two trays?

No. Small containers, hydroponic mats and other growing systems can work differently. But if you are using potting mix or coco coir in a standard tray, a drainage tray nested inside a solid tray is a practical and flexible starting point.

What to compare when buying trays

• Depth: shallow trays are easier to harvest from, but durability and root volume still matter.
• Drainage pattern: holes should distribute water across the tray instead of concentrating flow in a few places.
• Rigidity: thin trays can flex when wet or when carrying heavy media.
• Nesting fit: the upper tray should sit securely without binding.
• Reusability: durable trays cost more up front but may survive many more grow cycles.
• Cleaning: corners, ribs and channels should be easy to rinse and sanitize.

The affiliate-friendly lesson

Tray shopping is not really about finding one “best tray.” It is about matching durability, depth, drainage and workflow to how often you grow. That is how our future tray comparisons will be organized: beginner budget, durable home setup, rack system and higher-volume use.