
7 tips for indoor eggshell seed starts
I couldn’t wait for spring to get close enough for smart timing on seed starts this year (I’ve been deprived lately). So, January and February were spent experimenting with different lights, greenhouses, new containers, gestation periods indoors and all sorts of other crazy things a plant-loving soul might do to nurture growth in an environment not naturally conducive.
One of my most surprisingly successful larks involved egg shells. A post on Pinterest gave me the idea. I’m a breakfast person. I go through a lot of eggs. Since I was already buying what’s inside, I figured why not give the shell seed start container idea a shot?
It was amazing how fabulously these seemed to suit herb seed starts. So far, I’ve experimented with thyme, rosemary (slow gestation period), oregano, dill and sage. I’m testing parsley, cilantro, lavender, chives and basil this month with outdoor starts (bringing them in at night if temps are forecast below 45).
Out of all the containers I used (including a good number of not-so-cheap manufactured for purpose items – won’t use peat pellets again), herb seeds responded more fondly to the egg shells than anything else.
Seven lessons learned with eggshell herb seed starts
- One seed per container: These are small – don’t crowd root space. If you don’t have natural pour creases in the palm of your hand (that’s how I do it), there are manufactured tools available for such things, based on the seed size.
- Transferring soil to egg shells can get messy. The HVAC unit in my office failed (which has a nice and easy clean up area designed for all things produce), so I moved plant propagation and care to my kitchen. Soil spillage gets a bit more troublesome there. I wound up buying a turkey baster (this won’t work the way you think – take to top off, fill it then turn it upside down for the egg shell dump) for under $2. This proved to be an ideal soil transfer solution (many other experiments – not so much).
- Water lightly: a sprayer is essential – don’t try to do this with a watering can. It’s important, though, to keep the soil moist (not wet). Miss a day checking for dryness and you may lose your tender plants.
- Extra large are so much better: I tried this at first with large eggs (my usual cuisine choice). Going to extra large (for about 30 cents more a dozen) made a huge difference in how easy it was to break at the right spot and the size of the resulting container.
- Break at the narrower end: Granted, I’ve become a lot lousier at breaking eggs artfully since I started paying attention to the shell remains, but for ideal container results (and yokes that don’t break trying to squeeze through a hole too small), crack about 1/3 of the way down from the narrow end of the egg.
- Keep the cartons: While cardboard is better for plant health (over-watering is less of an issue), these get flimsy and challenging if you’re messy with how you water and are moving seed starts daily (from indoors to outside or to water and reposition under grow lights in an indoor greenhouse). Foamed plastics work better for daily transport. Just know water in the carton will get absorbed to make soggy soil in your egg shell (so transfer to dump liquid periodically).
- Aim for outdoor hearty early: the beauty of egg shell planters in egg cartons is they’re easily portable. Your seed starts with grow a lot faster if you can offer outdoor sunshine (and exposure to weather conditions including wind for more heartiness). Once temperatures are in the 50s, your tender starts will be happy outdoors (just acclimate them slowly – one hour to start with an hour added each day) if you have plants that have only been indoors.

Glorious green!
So, if you’re hankering for a seed start fix, try herbs in egg shells. You might be surprised at how happily they grow in these tiny (free) containers. Just make sure you remove the shells prior to transplanting outdoors or into larger containers.