Applying Calcium To Tomato Plants That Are Already Planted – A Step by Step Guide

July 21, 2011  |  7 Comments  |  by Ben Czajkowski  |  Do It Yourself - Gardening (DIY), Gardening
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At the beginning of the summer, I wrote a post on how to apply calcium into the potting mixture as you plant tomato seedlings, at the beginning of the growing season. This is normally good enough for about a month, at a time, in my experience.  Hopefully, at this point, your plants have tons of blossoms and lots of fruits. Maybe even some ripe ones!

Well, it’s time for another calcium application to help avoid things like blossom end rot, seen here:

Blossom End Rot

Blossom End Rot

ARGH! Luckily, this round only managed to take four little fruits. No sweat. I have dozens more across my plants.

Applying Calcium Solution To Tomato Plants

Materials needed:

  • Calcium tablets (can be purchases for $10 or so from Walgreens or another drug store)
  • Something to crush tablets (i.e. mortal and pestle)
  • One gallon pitcher or jug. An old milk jog works great. Then you can shake up water and calcium.
  • Hot Water
  • Tomato Plants
Calcium Mortar Pestle Jug

Calcium Mortar Pestle Jug

Steps for application:

  1. Place 6-8 calcium tablets into the crushing device. I like to do two pills per tomato plants. Since I have 4, plus a Sweet Million Cherry Tomato, I go with 8. This gives me more than enough.

    Calcium Supplement Tablets

    Calcium Supplement Tablets

  2. Crush.

    Crushing The Calcium Supplement Tablets

    Crushing The Calcium Supplement Tablets

  3. Ground these calcium tablets until it’s as fine as a powder as you can make it.

    Calcium Powder

    Calcium Powder

  4. Dump and dust the powder into the gallon jug.
  5. Using hot water, fill up your gallon jug. I like to stir as it goes along.

    Streaming Water

    Streaming Water

  6. Let the jug sit for a few hours, to come to room temperature. You don’t want to burn the plants’ root systems. Agitate the mixture every once in a while (AKA stir).

    Diluted Calcium Solution

    Diluted Calcium Solution

  7. Apply to your tomato plants, dividing it equally and stirring between applications.
Calcium Solution Next To Tomatoes

Calcium Solution Next To Tomatoes

Since I have sub-irrigated containers, I just pour the solution into the reservoir, and the roots soak up the calcium directly. You can apply this top-side, by just watering, if you don’t have self-watering or sub-irrigated planters.

I divide the mixture between the four tomato plants. For me, there is a little bit of powder in the bottom. I fill the container up with a quart of lukewarm water. Then I swirl the container vigorously and apply to my cherry tomato plant. I don’t love it enough to give it a full serving. It’s my red-headed step child.

Alternate Applications

If you need/want to skip the calcium solution, you can directly apply to the planting medium.

  1. Complete steps 1-3.
  2. Take powder and apply it to the potting mix or soil, around the tomato.
  3. Water.

You can also buy other organic mixes that you can use that might add other nutrients to the plants, as well.

If you have a favorite method of applying calcium, please let it in the comment section!

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7 Responses to “Applying Calcium To Tomato Plants That Are Already Planted – A Step by Step Guide”

You’re the only person I know, besides myself, who uses ground up calcium tablets on their tomatoes! I use Kirkland brand myself, as the come in the giant economy size. Heck, I toss in a handful of vitamins with minerals and a couple of aspirin, along with all my saved eggshells too. I use a coffee bean grinder for the capsules, then toss the mixture into the food processor with the egg shells. I use it in powder form when planting my seedlings, and later just scratch it into the soil around the plants.

tasty travels says:

Very cool tutorial Ben. I use eggshells and dolomite. If I have expired gums, I keep them for the garden too. I just blogged about finding BER this week. So far it’s only one cherry mato plant.

Yacouba Kone says:

I realy like those other answers about applying calcium on tomatoes. I use the oister shells meal as supplement before planting since that’s cheap here in Mali and I noticed great improvement of my soil’s in terms of calcium content. I just thought about this idea based on the fact that I use them as calcium source for chickens’ diet. I was happy with my result.

J Parker says:

At the flea market they sell the 300ct expired calcium pills for 1.00 each (South Carolina). The tomato plants never complain that the vitamins are expired. My way of doing this is use 4 tablespoons of Vinegar in a jar, drop in a few calcium pills and they dissolve into the liquid really fast. Mix this into 2 gallons of water and hit up your plants. No more than 2 tablespoon per gallon of vinegar to the water. The tomatoes like the slight acid boost and the calcium is liquidifed.

Horace C. says:

I use calcium tablets (12-15 600mg) in 8 oz of water to make a concentrate. I use my hand blender (like you use for soups, purees and smoothies) and use about 1oz to 1 gallon of water. seems to do the trick

Heather says:

Thanks for the advice, it was just what I was looking for!


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