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Tiny hands grabbing fistfuls of dirt, chubby fingers trying so hard to pick up itty bitty seeds, and laughter bubbling up as joy is found in getting dirty. Children, for the most part, seem to be fascinated with dirt and pudding, sometime at the same time, am I right?

And while I’m usually a big fan of keeping things clean (relatively), I can make exceptions for planting seeds in these easy egg carton seed starters. 

My own inner-two-year-old loves to get knee deep in dirt and watch things grow, so why not encourage my kids to do it too?

DIY Seed Starters

This is a super fun and quick DIY seed starter project you can do with your kiddos (or grandkiddos), and if you have one who doesn’t like to get dirty, it can be easily done at the kitchen table with a spoon and hardly any dirt contact at all. (Anyone have a dirt-phobe? We’ve got one!)

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Another great thing about this activity, is you can use an egg carton instead of throwing it in the trash can. Reuse, reuse! Those egg cartons are also compostable, so find out How to Compost, too! Here’s what you’ll need to make this activity happen:

Egg Carton Seed Cup Supplies

• 1 paper/cardboard egg carton
• potting soil (we used seed starting soil)
• flower/plant seeds (zinnias and marigolds are great for this!)
• low container or dish (I used a pyrex dish)
• water spray bottle (optional)

Egg Carton Seed Starters

Step One– Cut the top off of the egg carton and discard (compost!). Cut down the center, creating two pieces with six cups each. You can choose to leave the “cups” together at this point, or you can cut each cup so they’re separate. That’s the option we chose.

You’ll then want to use a sharpie to write on the outside of each cup what will be growing inside. Better yet, let your child who is learning writing skills do this. It’s super easy to copy the flower name from the seed packet right onto the cup, and it’s great writing practice!

Step Two: Let your little helpers begin to fill each egg carton seed cup with soil. They can do this by scooping with the cup itself (dirtier) or with a spoon (cleaner). Putting newspaper down makes clean up a cinch, so I highly recommend this!

Step Three– Have your little helpers place two or three seeds in each cup and lightly cover with soil. This is a great time to talk to your kids about how beautiful and wonderful things can start with just a tiny seed!

It’s also a great time to read The Tiny Seed by Eric Carle, even if your kids are a bit older, they’ll still love it, and they can try to mimic Carle’s artwork. 

Step Four- Place cups in a low container and water those babies! I did this at first with a water bottle, so I didn’t wash the seeds away. I also placed some water in the bottom of the dish itself, so the egg cartons would soak it up.

This helps to “water” the seeds from the ground up. Be sure to put your seed cartons in a sunny spot in the house, and keep them moist, but not soaking wet.

Covering Seed Cups

For more of a greenhouse environment, you can cover your tray with the egg carton seed cups inside  with saran wrap, or an equivalent wrap. This will help trap in moisture, and create a small greenhouse environment.

I find this cuts down on how often I need to water. Keeping the container near a warm spot (vent) or in a sunny place will also allow your seeds to germinate more quickly. 

You can also choose to store your seed cups in an old clamshell salad container. This created a perfect greenhouse environment for your growing seeds!

How long until seeds germinate?

Depending on what type of seeds you’re growing, you should see little seedlings popping through in a week or so. We grew marigolds, zinnias, and petunias, all things I love to have in the garden or in our window boxes.

The zinnias and marigolds came up pretty quickly, but we have to wait two weeks for the petunias… talk about an exercise in patience! I almost threw them out thinking they were duds. Don’t be like me; have patience… I hear it’s a virtue.

Remember, as your plants grow and you consider taking them outside to plant. You want to harden them off first (get them accustomed to the outside temperature). Read my full guide on how to harden off seedlings for detailed information.

You’ll do this by letting them sit outside during the day for a few days, and bringing them in at night. Then you should be able to safely plant them in your garden or container, like this DIY Self-Watering Planter!

What kind of seeds will you plant in your egg carton seed cups? I’d love to know what your kids think of this activity! Happy Gardening!