Seed Trays & Germination Plugs

The first things I'd ask before handing you a tray

Look, I know you just want to get those seeds in the dirt and see green ASAP, but hold your horses. Before you grab the first plastic tray you see, let's figure out what you actually need. If we were hanging out at the grow shop right now, I'd ask you three things:

First, are you popping seeds or taking cuttings? Clones usually need a bit more humidity stability than a hardy seedling. Second, what's your final medium? If you're going into deep water culture (DWC), starting in a peat plug is going to be a messy disaster. And third, how much space do you have? There's no point buying a 104-cell tray if you're only growing four plants in a closet.

Based on your answers, here is your perfect match

Alright, now that we've got that sorted, let's match you up. If you are a traditional grower who loves the simplicity of soil, you can't go wrong with the classics. Jiffy pellets are legendary for a reason—they are cheap, easy, and the roots love them. You just soak them, plant, and wait.

On the other hand, if you are planning a hydroponic setup, stay away from peat. You want inert media like rockwool or specialized propagation sponges. These don't mess with your pH and fit perfectly into net pots. And if you are looking for the absolute easiest, "I-don't-want-to-think-about-it" solution, go for a pre-loaded tray with organic plugs. They maintain the perfect air-to-water ratio so you don't drown your babies before they even start.

Why getting this right defines your entire harvest

You might think, "It's just a tray, does it matter?" Yeah, it does. A lot. The seedling stage is the most fragile moment in your plant's life. Using the right propagation gear means you avoid transplant shock, which is the number one reason for stunted growth in the first weeks.

When you use a proper tray or plug, the roots are air-pruned naturally. This creates a dense, healthy root ball rather than a spiraling mess. A strong start means the plant focuses on vegetative growth immediately after transplanting, rather than spending a week recovering. Basically, a better tray now equals a heavier harvest later.

Honest tips you won't see on the packaging

Here is some real talk from years of trial and error. First, don't drown them. Most newbies kill their seeds with kindness (and too much water). The plug should be moist like a wrung-out sponge, not dripping wet. If it's too wet, the seed rots. Simple as that.

Second, temperature is king. You can have the best tray in the world, but if it's freezing, nothing will happen. Use a heat mat if you have to. And finally, don't wait too long to transplant. Once you see white roots poking out the bottom or sides, it's time to move them to their final home, whether that's a big pot of quality soil or a hydro system.

Frequently Asked Questions about Seed Trays

Can I reuse my plastic seed trays?

Absolutely. Just make sure you wash them thoroughly with a mild bleach solution or hydrogen peroxide between grows. You don't want pathogens from the last run attacking your new seedlings.

What is better, peat plugs or rockwool?

It depends on your method. Peat is fantastic for soil and coco growers because it's organic and buffers moisture well. Rockwool is the standard for hydroponics because it's sterile and inert. Choose the one that matches your final grow medium.

Do I need a humidity dome?

For clones (cuttings), yes, a dome is almost mandatory to keep them from drying out before they have roots. For seeds, it helps during germination to keep the moisture in, but once the seedling pops up, you should usually remove it or open the vents to prevent damping off (fungus).

How long can seedlings stay in the tray?

Not long! These trays are for starting, not growing. Usually, within 1 to 2 weeks, your plants will have outgrown the plug. If the roots start circling or turning brown, you waited too long.