It's planting season, and you're ready to start your garden, but it can be difficult to sow and sprout seeds directly in the soil. Many don't survive, and weeds can interfere with the growth of your plants.
Instead of buying more plastic seed-starter pots or expensive kits, try using some free materials you'd otherwise throw out. Egg cartons and coffee grounds work great, and you'll be doing the environment (and your wallet) a favor. Let's dig in!
In This Article
- Supplies and Materials
- Planting Instructions
- Transplanting Instructions
- Repotting Instructions
- Frequently Asked Questions
Supplies and Materials
- Cardboard egg carton
- Potting soil
- Used coffee grounds
- A waterproof plate or tray to set the egg cups on
It's usually easier to cut your egg cups apart before planting.
How to Plant Seeds in Recycled Egg Cartons
- Mix your coffee grounds with potting soil and set aside. I usually make a half-and-half mixture of equal portions soil and grounds. A soup bowl full of this mixture should be plenty for this project. If you aren't a coffee drinker, don't worry! You can always stop by your local Starbucks and ask for used grounds. They're usually happy to give them away for free.
- Cut the cups of your egg carton apart. You can plant your seeds in the egg carton without cutting it apart, and you can also cut it apart after your seeds have sprouted, but I've found that doing it in the beginning helps to prevent your roots from getting tangled later. It also keeps you from accidentally crushing or breaking sprouts while trying to separate the cups later.
- Fill your individual egg cups about half full with the soil/grounds mixture. Keep the recommended planting depth in mind. You should be able to find this information on your seed packets. Some seeds will need to be planted deeper, so add less soil during this step for those seeds.
- Add the seeds. Be sure not to add too many seeds to each egg cup. Overcrowded seedlings will often die off. For larger plants like squash, I plant only one or two seeds per cup. For smaller plants like cilantro and parsley, I plant about four or five seeds per cup. Remember that not every single seed will actually sprout, but that sprouted seeds will need room to grow and soil resources for nutrients.
- Cover the seeds with a thin layer of the soil/grounds mixture. Once again, you'll need to keep the recommended depth in mind. Some seeds like more cover than others.
- Place the seed cups in a waterproof container. I use (and re-use) a disposable plastic dinner plate.
- Water your seed cups. Since your cups are in a waterproof container, you can simply pour water into the container. I pour water directly into the plastic plate rather than over the individual seed cups. The paper cups will soak up the water and keep your seeds moist. I maintain about a centimeter of water in the bottom of the plate at all times.
- Place your seed cups in the sun. Different plants have different sunlight requirements—your plants' seed packets should give you the particulars—but all plants need sunlight to grow. Be sure that your seed cups are in a place where they can get enough sun.
- Water your cups regularly. Enjoy watching your seeds sprout and grow!
When your seedlings are sufficiently grown, you can plant the cups directly in the ground.
How to Transplant Your Seedlings
The nice thing about using paper egg cups is that once your seedlings are sufficiently grown, you can plant them directly in the soil—paper cup and all. As you can see in the photo above, the roots will be able to grow right through the paper, which will eventually break down into compost once planted. The paper will also help your newly-planted seedling's roots stay moist until it breaks down.
How to Repot Your Seedlings
Some seedlings' roots may outgrow the egg cups before they're ready to be planted outside. When this happens, you can simply plant your seedlings (egg cup and all) into a larger flower pot or container.
I like to save disposable paper cups for this purpose. If the cups you use are biodegradable, they can be planted directly into the soil once your plants are large enough. Certain paper cups will eventually break down into compost just like the egg cups.
Frequently Asked Questions (FAQs)
Now we'll go over some common questions and concerns gardeners have about the egg carton planting process. If you have a question that isn't answered here, feel free to ask in the comments below.
What Type of Egg Carton Should I Use?
Egg cartons are typically made of paper, plastic, or styrofoam materials. Paper egg cartons are a much better choice for this project for several reasons:
- Styrofoam is not biodegradable and will not break down in the environment.
- Styrene, a major component of styrofoam, is believed by the EPA to be a potential carcinogen, meaning that it may cause cancer in humans and animals.
- Styrofoam is not water-absorbent and will not soak up and retain moisture for your seedlings.
Since styrofoam is made of such nasty stuff (both for people and the environment), it's a good idea to avoid buying eggs in styrofoam containers. Paper egg cartons are much safer, healthier, and more useful, both for this task and for other repurposing and recycling projects.
Are Egg Cartons Biodegradable?
Cardboard egg cartons are biodegradable, which means they will break down over time in the environment. These days, some eggs come in plastic or styrofoam cartons, which are not biodegradable. These should be avoided for the purposes of this project.
Why Coffee Grounds?
Coffee grounds are great for gardening because they add nitrogen, potassium, and phosphorus to the soil. When mixed with soil for egg-carton seedlings, they also help maintain a high level of moisture.
Questions & Answers
Question: Can I grow lemon seeds in an egg carton?
Answer: Yes! You can sprout lemon seeds using an egg carton. Here's a good guide on how to start lemon seeds: https://www.1millionwomen.com.au/blog/how-grow-you...
Question: Can you use this method for starting cactus seeds?
Answer: Cactus seeds should grow just fine, but you will need to make sure you use a sandy, loamy soil and I'd recommend planting only one seed per egg cup. Some may not sprout, but if you have two or more sprouts in a single cup, they'll be hard to separate with your fingers later because of the spines.
Emily on May 25, 2020:
wow this was so helpful I would have wasted my egg carton but this is a good way to make them useful
katie on May 13, 2020:
you can also use the egg shells - works like gem!
Hi on May 13, 2020:
can you use this for flowers too? specifically lavender/alyssum
Leslyn Harcourt on May 12, 2020:
So glad that l have these egg cartoons which l have been saving .l also have some egg plant seeds so l am going to get started using this method. Thanks for the helpful tips.
Ariel on April 18, 2020:
thank you for it this is a great way to plant during the stay home order.
Donna on April 18, 2020:
Thanks so much for this. I saved two egg cartons to do this, and your article is very helpful. Love using coffee grounds.
Kim on April 14, 2020:
I also am having some mold?? on my soul in my cups. I haven't gotten any sprouts yet but looks like two have some kind of bubble that looks about to burst? Hoping that's the germination??
Deanna on March 28, 2020:
This is great! I use this trick all the time, and it is a great way to reuse paper egg cartons. Good life hack!
Hannah on March 27, 2020:
Hi— anyone have trouble with soil molding while in the paper egg carton? I’ve been watering as recommended (and have some nice sprouting!!) but there’s a nice spread of fluffy white mold on my soil ):
Any suggestions are gladly welcomed
Kristen Howe from Northeast Ohio on May 03, 2015:
What a clever idea to reuse the egg cartons for growing seeds of herbs and what not. I might consider giving it a go this spring. Voted up for useful!
Susan Trump from San Diego, California on January 28, 2015:
This is great. I just bought little seed holders for 65 cents which I thought was a deal, but this is the perfect recycler. I'm going to leave the carton whole and put it in a glass dish to water from below. Then there will be gifts of sprouted seeds.
Cathi Sutton on February 12, 2014:
I do this too! I also use plastic fruit, pudding, and jello cups as reusable small "starting" pots for seedlings that transplant easily. I just poke a few holes in the bottom, fill them with my starting mix, and I'm off and running!
Tarrin Lupo from Peterborough NH on January 30, 2014:
Great idea, it will save me a few bucks on those plastic seed starting trays.
iluvceleb on January 04, 2014:
That's wonderful idea. I have a lot of egg plaatic containers, which we usually throw it away. This is very useful. Aside from cilantro and parsley, what are other seeds that i should try?
Fiona from South Africa on December 25, 2013:
Thanks for the tip on coffee grounds - I knew you could add them to compost and as worm food but had no idea that they were good for seedlings as well. BTW, I also use toilet roll inners, standing on a tray to sprout seedlings - they also work well.
Mary Craig from New York on April 10, 2013:
People like Wabash Annie, are probably familiar with using egg cartons but you are introducing them to a whole new, environmentally conscious age group. Great hub with lots of helpful pictures. I was especially impressed with the coffee grounds!
Voted up, useful, and interesting.
wabash annie from Colorado Front Range on April 08, 2013:
I used egg cartons many years ago and completely forgot about it. Thanks so much for reminding me what a great idea it is.