Week 16 For Tomatoes

Soil Amendments From The Kitchen

In an earlier post I outlined the various soil amendments that you might consider when you improve the soil for your tomatoes. I forgot to mention two soil amendments that I believe are quite beneficial. They are used coffee grounds and crushed eggshells.

Coffee Grounds

We make coffee every day but that does not produce piles and piles of coffee grounds. It does produce enough used coffee grounds for my tomatoes. There is a fair amount of misinformation on the Internet regarding the benefits of coffee grounds. Often mentioned is that coffee grounds are believed to be quite a acidic. That is not true. The were tested at a soil laboratory, using Starbucks coffee grounds, and it was determined that used coffee grounds come in with a pH of about 6.8.

Coffee grounds are often identified as a good source of nitrogen. That is only partially true. Coffee grounds will contain something over 2% of nitrogen, not irrelevant, but not major. Coffee grounds contain several substances that do promote healthy plant growth in addition to the nitrogen. They contain tanic acids and other minor nutrients.

The real value of used coffee grounds is that they are considered ice cream by earthworms. So if you sprinkle some used coffee grounds around the base of each of your tomato plants you will be sure that those plants are going to benefit from the valuable poop produced by those earthworms eating their ice cream.

If you want to use lots of coffee grounds, Starbucks and many other coffee shops give away the gallons of grounds they produce.

Crushed Eggshells

Crushed eggshells are a wonderful source of calcium, a mineral that is particularly valuable to fast growing plants such as tomatoes. Crushed eggshells contain about 95% calcium. We eat between one and two dozen eggs a week which might not seem like much but after 52 weeks you can have a pretty good pail full of egg shells. A lot of people will simply put the egg shells in a plastic bag and then break them up with a rolling pin and that works just fine. Nancy of course cannot be satisfied with only partially crushed egg shells. So every month or so she puts our collection of eggshells into the blender and ends up with a nice powder that is mostly calcium. It is that powder that we spread around the base of each of our tomatoes.

Perhaps the most important reason for using crushed egg shells on tomatoes is that calcium has been shown to prevent the common tomato disease called Blossom End Rot. If you have had that problem then you may want to start saving your egg shells.