Mary Ellen Ellis
There are many ways to start seeds, some more sustainable than others. If you can reuse egg cartons that you were just going to throw out, then it's a great step towards lowering your gardening footprint. Starting seeds in egg cartons is a fun, inexpensive way to repurpose them. Since you’re going to buy eggs anyway, simply remember to set aside and save the sturdy cartons.
These DIY seed starter pots work just as well as expensive, professional seed-starting trays – if you use them the right way. They're perfect for starting seeds indoors, and the individual egg cups are just the right size for many flower and vegetable seedlings. Once you have finished with them, the egg cartons can be planted in the garden or added to the compost bin, where they will break down and further enrich your garden.
Starting seeds in egg cartons couldn’t be simpler. All you need to be successful is paper-based or cardboard egg cartons. Save them up throughout the winter and ask friends and family to save them too.
Browse the finest flower and vegetable seed collections, professional-quality seedling trays, lids, and hydroponic grow kits in the Gardening Know How Shop.
Why Start Seeds in Egg Cartons?
There are a few great reasons to start using egg cartons for planting seeds, especially if you are a beginner gardener starting plants from seeds for the first time. Here’s why:
- An egg carton seed tray is so cheap it’s free. Gardening can be expensive at times, so any way you can trim some costs helps.
- Reusing materials is good for the environment. You were only going to throw it away, so why not find a new use for your egg cartons?
- Egg cartons are small, already compartmentalized, and easy to handle and use.
- The paper material allows for good drainage and aeration, aiding healthy root development.
- The shape of an egg carton makes it easy to situate on a sunny windowsill.
- Egg cartons are flexible seed-starting containers. You can use the whole thing or easily cut it apart for smaller containers.
- Depending on the type of carton, you may be able to put it right in the ground with the seedling and let it decompose in the soil.
- You can write directly on the egg carton to keep your seeds organized.
What You Need to Start
Paper-based egg cartons are the best choice for starting seeds, but you can use cartons made of styrofoam. The caveat is that the seedlings must be removed from the egg carton to transplant them, while paper-based cartons can be transplanted directly into the soil.
As an added option, you can even keep the used eggshells to make inner pots in the cartons. Growing seeds in eggshells can add vital nutrients to the soil, and they are easy to plant. You will need to crack your eggs carefully so that at least one half of each shell remains intact, then clean them before poking a drainage hole in the bottom with a needle.
Besides egg cartons, you will need, of course, seeds and a good seed-starting mix. While you can use a regular potting mix, the best egg carton seed starter is a soilless mix as it won't compact, allowing more aeration and water penetration. Soilless mixes also retain moisture better than other potting mediums and are sterile, which means seeds are less likely to contract disease.
Best Seeds to Start in Egg Cartons
Pretty much any type of seed will grow in egg cartons but the ones that will truly benefit from this method of germination are those that do not do well being transplanted. That means root crops, peas, beans, and small leafy greens can all be propagated in egg cartons, provided they are the biodegradable paper variety.
When the time comes to plant, you can simply cut away each individual cup to plant in its entirety. This alleviates potential shock the plant will go through if you disrupt its root structure while transplanting.
How to Start Seeds in Egg Cartons
Once you’ve obtained your cartons, seeds, and soil medium, it’s time to start planting! Simply cut the lid off the carton and poke some drainage holes into the bottom of the egg cups. You can put the container lid under the bottom of the carton, and any moisture will drain out and into the lid underneath.
Fill the egg cups with a moist seed-starting mix and plant seeds to the appropriate depth. How many seeds to plant per module depends on the type of seed. However, it is best to plant at least two seeds per cup as they may not all germinate.
Place the carton on a tray or in a shallow pan to catch any draining water, and position it in a warm spot
How to Look After Seeds in Egg Cartons
The key fundamentals of germinating seeds are to keep them warm and moist. It helps to put the egg carton in a plastic vegetable bag from the grocery store – another good way to reuse materials. This will create a more humid environment for the seeds. A warming mat can hasten germination but isn’t absolutely necessary as long as your room is warm. Once the seeds sprout, you can remove the plastic bag and set your container in a sunny, warm spot until the seedlings are ready to be planted outside.
Check the soil every day to ensure it hasn't dried out. Keep it consistently moist, never drenched. Using a little mister is a handy way to water without damaging the newly emerging shoots. How often to water seedlings depends on a variety of factors, so it's better to check the soil for dryness every day rather than watering to a schedule.
Once the seeds have sprouted, seedling care is the same as if they were grown in plastic trays. The seedlings will need plenty of light, so position the egg carton in a sunny windowsill or use a grow light. While seedling light requirements differ depending on the plant, most need at least 12 hours a day.
If you planted more than one seed per egg cup, then you will need to know how to thin seedlings so you can focus your energy on only the best young plants and give them room to develop roots. Where you have too many good quality seedlings, the extras can often be planted into individual pots.
How to Transplant Seedlings Grown in Egg Cartons
When the last frost date has passed and it is time to transplant seedlings into the garden, it's important to prepare them for their change of environment. Harden off seedlings by placing them outdoors for a few hours each day, gradually increasing the duration over the course of a week.
When planting, simply cut through the carton, freeing up each individual egg cup, and then plant the seedling inside its egg-shaped vessel directly into a prepared garden bed. The egg cup will biodegrade into the garden.
More Growing Inspiration
- Why are my seedlings wilting? Discover 6 common causes, how to diagnose problems – and how to save your precious baby plants.
- Browse pro-quality seed-starting kits in the Gardening Know How Shop – including seedling trays, humidity domes, and drip-irrigation lids.
- Learn the benefits of using a humidity dome seed propagator for faster growth and healthier plants.
- Not sure how deep to plant seeds? Get it right every time with this simple trick.
- Sign up to the Gardening Know How Newsletter for regular growing advice, plant inspiration, and exclusive offers.
