Application of Calcium to Tomato Plants

Application of Calcium to Tomato Plants

Sun Jul 13, 2008 3:52 pm

I had read that epson salts can be used to get calcium to the plants. How do you apply and what type of mixture? ALso are there any other ways to get calcium to the plants. Some of my Tomato's are experiencing "cat facing" and since I water regularly I'm wondering if calcium deficiency is the problem. Thanks for the help.
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Mon Jul 14, 2008 10:23 am

"Cat-facing" is not usually a result of a calcium deficiency; a calcium deficiency will be [usually] indicated by blossom end rot.

But to answer your question, calcium sources -

--Egg shells- best added when you place them underneath the plant at planting time; but you could add into the soil whenever to gradually bring up traces of calcium.
--Liming the soil with calcium carbonate [crushed limestone.] Best in the winter or off season, or before planting.
--There are commercial sprays available [calcium nitrate & calcium chloride] that you can spray on or around the plants themselves during the growing season.

Calcium may be present in abundance and still not taken up by the plant; uptake can be supressed by a number of causes [water deficiencies or irregularities; magnesium/nitrogen/potassium excess in soil; high humidity or excessive transpiration in the plant; high acidic soil, etcetera.]
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Tue Jul 15, 2008 3:58 am

On my Epson Salt bag directions are to add 1teaspoon for every foot of tomato plant every two weeks.
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Tue Jul 15, 2008 11:36 am

Soft rock (aka colloidal) phosphate is about 16% calcium and both the phosphorus and calcium have relatively high availability.
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Wed Jul 16, 2008 12:39 am

I had a problem with blossom end rot on my Romas and tried a completely nontraditional calcium supplement. My husband the chemistry teacher was worried about using calcium chloride, and while we have plenty of calcium carbonate in the form of limestone around here, we knew that would be very, very slow to get to the plants. So I dusted lightly around the base of the plants with dry mortar mix powder -- not too much because I didn't want a concrete mulch! The Romas are looking much better a few days later, no new blossom end rot, but I can't say whether that's because of the mortar mix or because of the rain we've gotten in the last couple of days.
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Wed Jul 16, 2008 4:37 pm

What did you decide?

I just found 3 tomatoes with BER, and am afraid one of my largest is developing it. I cannot find that spray anywhere around here (NYC), and would love to save my fruit!!
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Thu Jul 17, 2008 1:12 am

Well, I can't be sure it helped, just that something helped. But the end of finding new BER was two days after applying mortar mix. It surely didn't hurt.
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Thu Jul 17, 2008 10:32 pm

Epsom salt is magnesium sulfate. It does not contain calcium.

I ground up a couple dozen calcium citrate dietary supplements, dissolved it in water and watered my tomatoes with the solution when I has blossom-end rot. It stopped the rot immediately--all the tomatoes which ripened before I added that calcium had blossom rot, and none of the ones which ripened afterwards had it.

This is a good way to do a plant or two, but would get expensive if you had more plants than that. Maybe there's a bulk source for calcium citrate.

For those who are novices (like I am) "blossom end rot" is when the end of the tomato opposite the stem is off-color and mushy (like it's starting to rot) while the rest of the tomato is healthy.
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Wed Apr 14, 2010 12:21 am

Kale is actually higher in calcium than milk. I used a blender to pulverize some kale in a little soapy water - then I added some molasses for good measure. I'm going to water my tomato plants with this mixture and see what it does....The only concern I have is that the kale may provide too much nitrogen....
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Wed Apr 14, 2010 12:38 am

Intriguing idea but why did you add soap?
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Wed Apr 14, 2010 12:51 am

Just a small amount (a drop or two) because I read in Jerry Baker and other places that soap helps to "feed" plants by carrying the water further through dense or impacted soil. The soil I have in my yard is really dense and sandy....
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Wed Apr 14, 2010 3:40 am

Sheet rock mud works great to prevent blossom end rot. Get a large hand full of sheet rock mud and stir it into 5 gallons of water. After planting your tomatoes plants give them a quart jar of water. I guarantee you won't have blossom end rot.

If you don't have sheet rock mud dissolve some sheet rock scraps in 5 gallons of water.

This works better than lime.
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