If you are already using lime then your calcium problem is resolved at the same time. Dolomite lime is most often recommended but either form provides Ca.

As already discussed in the many other posts on Ca and tomatoes (especially on the Tomato forum here), the issue is not Ca++ ion deficiency in the soil and milk or TUMS or egg shells, etc. provide no benefits. The issue is uptake and distribution through the plant and that is a soil moisture issue.

May I ask how you know for a fact that your soil is Ca deficient? Is this from a professional soil test? If so then it should have included a recommendation for the amount of lime to use.

Dave

If you are using something like Tums or Rolaids, they are Calcium Carbonate. So is ground limestone and its a whole lot cheaper. if your magnesium is high, just avoid Dolometic limestone. Just add until your pH is where you want it.

My BIL just built a new bed and asked if I laid my toms on their side to plant. I told him I dig a deeper hole and go straight down, as there is a higher likelihood of soil moisture the deeper you go. The BH also takes Tums and I kept an expired bottle and put a crushed one at the bottom of the hole just in case (less Ca IIRC than Dolomite lime). Anyway, very little problem with BER, maybe once when we were gone and early heat wave hit. Water deeply.

Dan

I had a soil test done by the state lab, we applied limestone but calcitic not dolomitic b/c the Mg was so high. But the soil is so acidic it will take multiple applications and years to adjust the pH. I don't know how much 1 application affected the Ca since I have not tested since. I plan on amending the soil in the rows, and figured on adding Ca supplement in tomato planting holes.

I don't think adding lime directly to holes when planting is a good idea, Square Foot Gardening recommends 1/2C lime per 4ft long trench per month (surface application). Says nothing about liming the trench when you are preparing it. Now, if I were to mix the lime with the coffee grounds/leaves/soil at the bottom of the trench, perhaps it wouldn't burn the roots. Am I correct in assuming that an alkaline material like lime would burn if in direct contact with roots? So I want to avoid pockets.

NC State just recommends 3/4C lime (plus fertilizer) applied "per plant", doesn't say how deep to work it in (6-9" like they recommend with OM, for clay or sandy soil?) or per "soil test recommendations". My soil test recommendations were very general, and the PhD I spoke to about interpretation agreed that too much lime was recommended for my blueberry patch, so I really don't have any confidence that the lime recommendations are specifically for Ca requirements for tomatoes in this area, they may have been based on simply getting the pH close to neutral. Do pH and Ca go hand-in-hand, so closely that once the pH is in the mid 6's, the Ca will be OK for tomatoes (but not too high for other "veggies" - OK, really all I'm growing is fruit LOL)?

pH was 4.4, lime (I assume dolomitic) was recommended 202 lbs for 1000sf. We applied 60 lbs/1000sf of fast-acting calcitic lime back in April. I guess the only thing I can do is bring in another sample for testing but it's getting a little late for planting - I've got to get these tomatoes out of the pots, some of them have been repotted twice! And then I don't want to lime the whole area again right now - I just want to adjust the pH, Ca, and N in the trenches where I'm planting, mulch the aisles, then till everything in, lime again, and plant a cover crop after harvest.

We never had problems with BER in old spot but there Ca and Mg were "very high" and N was "medium" after a couple years of amendments.