I use marble dust. I have never had great success with anything else.

If your growing just a few plants in your home garden, try putting all your egg shells in the compost and you shouldn't have any trouble with blossom end rot.

This may be interesting, maybe even useful.

Our favorite tomato expert Carolyn137 wrote an excellent response to a question about Blossom End Rot (BER) and I am quoting it here:

With BER there is NO problem with absorption of Ca++ though the roots. The problem is maldistribution within the plant that can be induced by a number of stresses which include uneven delivery of water, too much N, growing in too rich soil, too hot, too cold, too wet, too dry you name it.

As the plants mature they can better handle the streses that can induce BER so usually it goes away.

The two exceptions are first, if the soil has NO Ca++ as confirmed with a soil test, and that's a rare condition, and second, if the soil is too acidic in which Case Ca++ is bound in the soil.

Again, adding lime, egg shells and on and on can not and will not prevent BER b'c absorption of Ca++ thru the roots is OK.

Paste tomatoes are especially susceptible to BER and I think someone in a post above mentioned that.

If you go to the top of this first page and click on the FAQ link and scroll down you'll also find an article about BER in case some of you have never looked at the FAQ's And there's some darn good articles there as well, but I wouldn't pay any attention to the variety list b'c it's way out of date.

The old information about BER being caused solely by lack of soil Ca++ has been shown to be wrong with research that's been done in the last 20 years or so, but it's going to take another generation before the real story gets into books, websites, magazines, etc. Most of the better websites already have the correct information.

BER affects not only tomatoes, but peppers, squash, cabbage, cauliflower, etc., and it's a huge multimillion dollar problem for the industry, which is WHY all that reasearch was done. For instance, when tissues were taken from a plant that has BER fruits and was assayed for Ca++, the normal level of Ca++ was found, it just wasn't getting to the blossom end of fruits. And there's also a condition called internal BER where the fruits look fine, no evidence of BER externally, but when you cut open the fruit the inside is black

Hope that helps

So, unless you have had your soil professionally tested, and it is calcium deficient, adding calcium will make no difference.

Betsy

Yes, Carolyn is right. Best solution to BER, is to have a lot of organic matter in the soil to buffer water fluctuations. I have almost desert like sandy soil which is very conducive to BER. I require a ton of organic matter in order to grow anything, but I've yet to experience BER because of the amount of organic matter I use. It's really about maintaining even moisture on the roots. This also works for clay soils too that are too water retentive which also causes BER.

I should mention mulching in addition to OM also helps evens out root moisture, especially in sandy soils.

BER FAQ

Here is a link that might be useful: FAQ: BER