Eggshells
Eggshells contain calcium, which is useful for tomatoes. However, you need to prepare the eggshells in order to make the calcium more bio-available for the plants. This simple tutorial will show you how.
Eat Some Eggs!
First step is to eat a bunch of eggs. We generally have eggs for breakfast, and save the shells in a plastic container. As the container starts filling up, we compress the shells to get more space. Once they can no longer be compressed, it's on to the next stage.
Cooking
Set the over to 180 degrees F, put the eggshells on a tray (we also put parchment paper on the tray, which helps reduce cleaning -- for our regular cooking, as well), and leave them in the oven for a few hours (3 or 4).
Blending
Remove the eggshells and put them in a blender. Be careful, they'll be hot. We usually spoon them in until there aren't a lot left, and then lift the parchment paper by two opposite sides and "pour" the remainder into the blender. Blend until a fine powder; sometimes it helps to use a spoon to push down on the top, but of course be careful not to blend the spoon!
Secret Ingredient: Vinegar
Put the eggshell powder into a container to mix it in. Note that the vinegar will cause some foaming, so the container should be large enough to contain the foam as well. Best to start with small amounts, to get used to how much causes how much foam, etc. For each cup of eggshell powder, we add a half cup of distilled white vinegar (5%), from the grocery store.
Mix thoroughly, allowing the foam bubbles to pop and subside. Keep the container closed, after you've ensured the pressure has released of course! We are using a plastic 40 oz mixed nut jar, and have done this twice and are about to do it a third time, into that container.
Put Eggshells Under Tomatoes
We have three huge tomato plants that we got from Costco a few days ago for $15 (all three in one pot, so I don't think I'll be able to easily separate them, but that's okay), as well as several other smaller starter tomato, squash, cucumber, and several pepper varieties.
When planting the tomatoes, we will dig a hole deeper than we need (perhaps 3 inches deeper?), and will spoon in some of the eggshell/vinegar mixture, then add a thin layer of soil, perhaps 1/8" or so. Then put the tomato plant in, and remove the lower branches that would be underground -- the tomato plant will grow additional roots from the buried stem.
That's it! As the tomatoes grow, the roots will reach down and bring the calcium up from the bio-available mixture below them.
Good luck with your garden!