What Can You Use As A Seed Tray? (10 Seed Tray Ideas)


If you are looking to start seeds for your garden indoors, you will need some type of seed tray.  You can use an “open” seed tray, or you can use one with individual cells, and there are lots of options.

So, what can you use as a seed tray?  You can make a seed tray out of aluminum catering trays, cupcake trays, glass pans, wooden boxes, cardboard boxes, egg cartons, plastic containers, plastic clamshells, or ice cube trays.  You can also buy ready-made seed trays (with or without individual cells) from many retailers.

Of course, you might need to do a little work to prepare some of these items for seeds.  For example, you will need to drill drainage holes in some of them.

In this article, we’ll talk about what you can use as seed trays and when to use each one.  We’ll also mention some cautions to keep in mind.

Let’s get going.

What Can You Use As A Seed Tray?

There are tons of items you can use to make seed trays, and some don’t require too much work to prepare.  Here are 10 ideas for seed trays:

  • Aluminum Catering Trays
  • Cupcake Trays
  • Glass Pans
  • Cardboard Boxes
  • Egg Cartons
  • Wooden Boxes
  • Plastic Containers
  • Plastic Clamshells
  • Ice Cube Trays
  • Manufactured Seed Tray (from a retailer)

Let’s start with a simple but effective option: an aluminum catering tray.

Aluminum Catering Tray

Aluminum catering trays are those shiny, rectangular trays you often see at events where you need to serve food to lots of people.  They vary in size, but these trays are often 2 to 4 inches deep (plenty of depth for seed starting).

aluminum trays
Aluminum trays are one option for seed starting.

If you want, you can use the aluminum tray as a single “open” tray (without cells to separate the seeds).  However, you will need to cut or drill drainage holes in the bottom of the tray (do this carefully!)

If you want individual cells (or you don’t want to drill holes), don’t worry.  Simply get a bunch of individual pots – one for each seed.

For example, you could use a small plastic pot for each seed, and then line the pots up in rows inside the aluminum tray.  The tray will catch any water that drains out of the pots when you water them.

As an added bonus, an aluminum tray would easily transfer heat from a seedling heat mat to the soil and seeds.

You might be able to find a plastic cover that fits an aluminum tray.  This will act as a humidity dome to keep the soil and air moist for improved germination rates and speed.

You can learn more about humidity domes in my article here.

If you cannot find a custom-fit cover, you can use plastic wrap.  Just be sure to let the tray breathe if it gets too warm!

plastic wrap
Plastic wrap will help to trap heat and moisture in the air and soil underneath.

The ideal temperature for seed germination varies by plant.  However, a temperature of 75 degrees Fahrenheit (24 degrees Celsius) should work well for most vegetable seeds.

You can probably get some leftover aluminum trays from a catering company if you ask.  You can also buy a pack of 10 (or 50) aluminum catering trays from Webstaurant Store.

An aluminum tray would be a good choice for starting lots of seeds in bulk (such as onions).

Cupcake Tray

Cupcake trays (or muffin trays) come in all shapes and sizes.  It is common to find ones with 6 or 12 cells, but you can also find trays with 9, 24, and probably other cell counts.

cupcake tray muffin tray
Cupcake trays – not just for baking! They can make good seed trays to hold small pots.

Some cupcake trays are made of thin aluminum, so they might not be sturdy enough to hold the extra weight of pots.  For those, I would suggest drilling a hole in each cell and filling it with soil to plant your seeds.

Other cupcake trays are made of hard metal, so it would be difficult to drill holes in them for drainage.  For those, I would suggest using each cupcake tray cell to hold a small pot with a seed in it.

For larger pots, use a larger tray with fewer cells (perhaps a 6-cell tray).  For smaller pots, it makes sense to use a tray with more cells (12 or even 24).

You might be able to get an old cupcake tray from a bakery or from a friend who wants to buy new trays.  If not, you can buy some from the Webstaurant Store – here are a couple of options:

Cupcake or muffin trays would be a good choice for starting seeds where you need fewer plants (for example, summer squash).

Glass Pan

As with the other items listed above, glass pans are useful for baking.  However, you can also use them as seed trays.

glass pan baking
A glass pan is a good option for a seed tray if you are starting seeds in many small pots.

You won’t be able to drill holes in a glass pan without breaking it.  Instead, it is best to use a glass pan as a tray to hold individual pots.

Put each seed in its own plastic or clay pot.  Then, line up the pots in rows inside the glass pan.

The pan will catch any excess water that drains out of the pots after watering.  (This is helpful if you don’t want to make a mess of your house!)

Glass is sturdy enough that it can hold plenty of weight (water, soil, and even clay pots).  However, you aren’t limited to clay or plastic pots.

You can also make your own small pots out of plastic.  Just take a small water bottle, cut off the top, and drill some drainage holes in the bottom.

water bottles
Cut the top out of a plastic bottle and drill drainage holes in the bottom to make a pot for growing seeds.

You could even make pots out of pieces of cardboard if you want.

You can learn more about ways to use cardboard in the garden in my article here.

A glass tray would easily conduct heat from a seedling heating mat to the soil and seeds.  The only drawback is that you will have glass shards everywhere if you ever drop the tray.

Cardboard Box

Cardboard is very versatile in its garden uses: plant collars, mulch to smother or prevent weeds, pots, and even seed trays.

cardboard tubes
Cardboard can be used to make plant collars (to protect plants from cutworms) or to make seed trays.

One good option for a cardboard seed tray is a box you might get from a candy store for a box of chocolates.

Cardboard is biodegradable, and you can add what is left to your compost pile after you transplant your seedlings outside.

However, there is a major drawback to using cardboard for a seed tray.  If the cardboard gets too wet, it will break down and become soft.

At that point, it will be difficult to move it to the garden without it falling apart.  However, you might be able to carry the whole thing outside in another larger container.

You could also use a cardboard box to hold a bunch of individual plastic or clay pots.  However, if the pots are too heavy, the cardboard might not hold up.

Egg Carton

An egg carton is a cool way to make a recycled seed tray.  Each individual cell in the carton can hold a seed (instead of an egg).

egg carton
An egg carton already has individual cells you can use to start seeds.

Egg cartons are feasible for a large volume of seeds, since they are very easy to come by.  If you ask a few friends to save cartons for you, they will really start to add up quickly.

If you want, you can buy a bunch of egg cartons, such as this 20-pack from Webstaurant Store.

Egg cartons come in many different cell counts, including 6, 10, 12, and 18.  There are also different cell sizes available (for example, chicken eggs vs. quail eggs).

Cardboard egg cartons are biodegradable, so you can put whatever is left in your compost pile after transplanting your seeds into the garden.

As with cardboard, the drawback of egg cartons is that they get soft when wet.  By transplanting time, the cartons might to so weak that they fall apart when you try to move them into the garden.

You can solve this problem by keeping the egg carton on another tray (metal, wood, or plastic) and moving the whole thing into the garden to transplant.

You can even split an egg carton into smaller parts.  For example, a 12-cell carton would give you 3 4-cell cartons if you cut it into pieces.

This would be useful for keeping track of different varieties of the same plant.  You could attach a plant label to each individual egg carton or section to tell you what is growing (and when you planted it).

Wooden Box

A wooden box is another option for a seed tray.  You can find a wooden box or tray in your house, build one from scratch, or buy one online (such as these wooden craft display boxes from Etsy).

wooden tray glass jars
A shallow wooden box or tray can work as a seed tray. If you don’t use pots, drill holes in the bottom for drainage.

To build a wooden seed tray from scratch, you need a flat rectangular piece of wood for the base.  You would also need 4 long, thin pieces for the edges (you can make the tray as tall as you like, but 2-3 inches should be ok for seed starting).

Attach each edge piece to the base with nails or screws.  To make things easier, drill drainage holes in the bottom of the wooden box before filling it with soil.

One drawback of wooden box seed trays is that they will rot over time.  Being in contact with wet soil will speed up the decay of wood – and with seed starting, it is hard to avoid this!

Of course, you could line the wooden box with plastic to keep the wood from getting wet.  If you do this, just make sure to put holes in the plastic to allow for drainage (the wood on the bottom part of the tray will still get wet).

Plastic Container

A plastic container is a long-lasting option for a seed tray.  You have two options for such a container:

  • Drill drainage holes in the bottom and use it as an “open” tray without individual cells
  • Use a small pot for each seed and line up the pots in the tray.

It is easy enough to drill through plastic for drainage holes, but be careful when you do.  You can use almost any plastic container for a seed tray.

plastic containers
You can use almost any plastic container as a seed tray, as long as you put drainage holes in it.
Image Courtesy of:
Stebulus via:
Wikimedia Commons: https://commons.wikimedia.org/wiki/File:
Tupperware_translucent_blue.jpg

However, your best bet is something on the shallow side, such as this 2.5 inch deep polypropylene food pan from the Webstaurant Store (also available 4 inches deep).  These trays are easy to carry, and you can find a matching cover to keep heat and moisture inside.

A plastic seed tray is a good bet for starting a larger number of seeds all at once.

Plastic Clamshell

A plastic clamshell is another good option for a seed tray.  You can find clamshells with one big “open” cell, or ones with individual cells.

plastic clamshell raspberries
A plastic clamshell that holds produce can also be used as a seed tray.
Image courtesy of user RIsheehan via Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Clamshell_Pack_002.jpg

For example, here is a set of 25 6-cell plastic clamshells and a set of 50 12-cell plastic clamshells from Webstaurant Store.

You can probably use some plastic clamshell containers from food you buy at the grocery store.

Plastic clamshells won’t break down after contact with water and soil.  However, they might become brittle and start to crack if Ieft out in the summer sun.

Ice Cube Tray

An ice cube tray is a good option for starting seeds that you want to transplant into a small pot after germination.  Ice cube plastic is a little thicker than plastic clamshells, but you should still be able to drill into the bottom of each cell to make drainage holes.

ice cube tray
An ice cube tray already has separate cells for seed starting.
Image courtesy of user Prattflora via Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Ice_cube_tray.jpg

You can use any ice cube tray for seeds.  To save money, see if you can find one from a friend’s old freezer.

You can also buy your own ice cube trays – some common sizes are 12 or 16 cells.  However, you can also find ice cube trays with fewer but larger cells, such as this silicone 4-cell ice cube tray or this silicone 8-cell ice cube tray from Webstaurant Store.

Ice cube trays would be good for keeping different varieties of the same plant separate (such as multiple tomato varieties).

Manufactured Seed Tray

Some trays are manufactured specifically for seed starting.  They have drainage holes built-in, and some of them have individual cells.

seed tray
Seed trays come in all shapes and sizes. You can find some with dozens or hundreds of cells!

You can find seed trays in various sizes, from 6 cells all the way up to 1000 cells!  Whether you are a casual beginner gardener or an enthusiastic master gardener, there is a seed tray for you.

You can learn more about seed trays in my article here.

Conclusion

Now you have some ideas for what to use for seed trays.  You also know when to use each one, along with what to look out for.

You can learn more about what seeds need to germinate in my article here.

You might also find it helpful to read my article on what seeds to start indoors (to transplant out later in the season after the soil warms up!)

I hope you found this article helpful.  If so, please share it with someone who can use the information.

If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here.  Enjoy!

~Jonathon

jonathon.david.madore

Hi, I'm Jon. Let's solve your gardening problems, spend more time growing, and get the best harvest every year!

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