Don't Toss Old Egg Cartons When You Could Be Using Them For Your Plants

There are several tutorials online for repurposing cardboard egg cartons as seed starters. They're especially convenient for this because you can transplant the seedlings to larger containers or gardens, carton and all, since the cardboard will decompose. But what if you buy eggs that come in clear plastic cartons that aren't biodegradable? Not to worry, these cartons can still serve as containers to start seeds. 

In fact, with a little prep (and some empty eggshells) the clear plastic cartons can basically be used as tiny greenhouses. The closed plastic lid can help to generate high humidity ideal for starting seeds. By doing this in a little DIY greenhouse outdoors in winter, you may even ensure that your seedlings can skip an involved hardening off process — that is, getting indoor-grown seedlings used to outside weather. Because they'll harden off naturally, you can just plant them right in the garden when the soil has warmed in spring.

To begin this project, in addition to your clear plastic carton, you'll need something sharp (like a nail), soil, permanent markers, and, of course, seeds. Empty egg shells cracked into halves are optional. It's best to use a sterile soil mix to plant your garden seeds. Although soil gathered from the outdoors might work, it's possible that this soil would contain fungus, bacteria, or weed seeds. 

January or February is a good time to start the winter sowing process. To begin, use the nail to poke some holes in the tops and bottoms of each egg compartment. The holes on top will allow for air circulation in the container, which is a requirement in greenhouses for disease prevention. The holes in the bottom are for drainage, as roots can rot if they're left to soak in standing water. 

One optional step is to have the shells serving as the "pots" for your seeds. After cleaning your eggshells (try baking them for five minutes at 400 degrees or just rinsing and drying them), carefully poke an additional drainage hole in the bottom of each. Place them in all of the compartments in the carton, then fill each shell with soil. Alternatively, if you didn't save eggshells or would prefer not to deal with potential egg mess, you can also cut out the inside compartments of a cardboard egg container or roll little cup shapes out of newspaper.

Plant your chosen seeds in the soil, give each a little drink with a spray bottle, and shut the lid. Make sure to label what seeds you've planted where with your permanent marker. Find a spot outside where they'll get plenty of sun and rain, but make sure the location is shielded from strong winds. Once it's time to transplant your seedlings, crush the eggshells before you plant them in the ground. The decomposing shells can nourish your garden.