So I was checking out my garden the other day all excited about my developing tomatoes when I suddenly noticed quite a number of tomatoes whose ends where brown and shriveled. I immediately knew what it was, Blossom End Rot (BER). I almost always get this on a small number of tomatoes, but this was a larger problem and, though disappointing, I was not hugely concerned because BER is not a disease but rather a sign of a Calcium deficiency.

Blossom End Rot

This can be either caused by an actual deficiency of Calcium in the soil or because not enough is being absorbed by the plant. Dry or overly acid soil can be causes of insufficient Calcium uptake. To fix a dry soil deficiency, simply increase your watering.

For acid soil or actual Calcium deficiency the solution is the same, add lime to the soil. Lime comes in two general forms Dolomitic and Calcitic. Both types of lime contain Calcium, but Calcitic has higher amounts of Calcium while Dolomitic has a mixture of Calcium and Magnesium (which is a mineral that plants also need though usually not as much as Calcium).

Ideally, to determine whether the problem is an actual Calcium deficiency you should get a soil test, but that can take a couple of weeks and you could lose a lot of tomatoes in that time, so what I did (and recommend if you see BER in your garden) was add lime to my garden. I like a product called Espoma Organic Traditions Garden Lime, it’s available at most garden centers and nurseries. I added it to my garden, watered it in and have had no more BER since. I also removed all of the affected tomatoes because, although the upper part of the tomato will ripen, it will use energy that otherwise would go to growing more completely healthy tomatoes.

If you want to get a soil test, you can go to the Cornell Nutrient Analysis Laboratory and download forms and instructions to get your soil tested for pH (acidity), assorted nutrients, and some heavy metals. It’s not a bad idea to get a soil test every couple of years, although I’ve actually never gotten one and still had good results. If you add compost to your garden regularly you should have a good mix of the proper nutrients.

I think, without proof of course, that my Calcium deficiency may be a function of the fact that the beds where I’m growing the tomatoes is a new bed and that the compost may not have decayed enough to make enough Calcium available to the plants. As a result, I’m recommending that when initially constructing a lasagna garden bed that lime be added to the top compost layer.

So don’t panic if you see Blossom End Rot and remember, in just a few short weeks we’ll be swimming in tomatoes. Can’t wait!