Foliar Feeding with Calcium Chloride

Foliar Feeding with Calcium Chloride

Foliar Feeding with Calcium Chloride

A Fast Fix for a Common Garden Problem

By Frazer Love


Here in the South (Georgia, USA) we experience long periods of high humidity, high temps, and very little wind. We call it sticky. It stays sticky down here, and with these conditions it’s all too easy to experience calcium deficiency. I’ve lost too many tomatoes this year to blossom end rot. At first I thought I hadn’t amended the soil well enough, or maybe it was the pH that was out of whack. After having the soil tested it was easy to see why I had been experiencing blossom end rot. Elemental levels were good; 6.2 pH was perfect. There could be only one other possible cause. I was at the mercy of Mother Nature.

Since calcium is an immobile element within a plant, it meant that its dependence on the xylem’s pull of water up the plant, itself dictated by transpiration rate, would fall victim to our sticky southern days. If the days were sticky, that meant the plant’s transpiration rate was almost completely shut down.  This was especially evident on the tips of the new shoot growth. They were yellow, soft, and stunted. I knew I had to correct this problem immediately, with a calcium foliar feed, if I had any hopes of saving my summer crop of tomatoes. And with the persistent high humidity, it meant I’d be doing this once a week for an extended period of time. So far I’ve only had to make three applications since first signs in early June. I picked a top tomato off this morning that had blossom end rot. It looks like another application is due. Side note, prevention is always best. I should have never stopped my applications unless I had seen toxicities.

Transpiration & Evaporation: Factors Effecting Calcium Use and Demand in Crops:

| CLICK HERE | If you can’t see the Video below

[youtube width=”560″ height=”315″ video_id=”TeR_fLRDrZg”]

You may know that not all calciums are created equal. Typical fertilizer forms of calcium include calcium nitrate and to a lesser extent calcium chloride. When it comes to foliar applications we must be more precise with our choice of calcium. Fertilizer grade calcium nitrate can easily burn the bracts leaving you without a blossom to bloom. At least then you won’t have to worry about blossom end rot. You won’t have any blossoms to rot. In all seriousness though, there is but one truly safe way to apply calcium to the plant through the leaves. It is recommended that you use “reagent*” or “laboratory*” grade calcium chloride.

* want to learn more about fertilizer materials and grades-it DOES matter, after all…click | HERE |

Calcium chloride is available in the dihydrate or anhydrous forms; dihydrate is usually less expensive. Fertilizer grade calcium nitrate may contain impurities than will burn the leaves and bracts of the plant. However, horticultural grade calcium nitrate has also shown effective at correcting deficiencies without burning. There are several companies out there that you can most likely find at your local garden supply shop. Examples include: Cutting Edge Solutions Plant Amp, Monterey’s Foli-Cal, and Southern Ag’s Stop Blossom End Rot. I prefer Plant Amp from Cutting Edge Solutions due to it containing organic acids making it perfect as a foliar (foliar sprays need to be slightly acidic in order to more easily pass through the stomata). If you add Cutting Edge Mag Amp, a magnesium supplement, you won’t need a surfactant because it’s already in the mix. If not, make sure you use some sort of wetting agent, like soft dish soap at a rate of 2TBSP per gallon.

When applying a foliar spray it is important you test the spray on a small section of the lower portion of the plant, and if you have a variety of plants use one from each variety as a test. If there are no signs of burn within 3-4 days, it’s safe to proceed. With calcium chloride foliar sprays it’s important that you apply out of direct sunlight. If applied in direct sunlight, there will be severe leaf damage. You may even lose a growth tip to burn. Application in the early morning is safer especially when you have high humidity which can lead to Botrytis or Grey Mold when the application doesn’t dry completely before the sun sets. Apply once a week for 3 consecutive weeks upon first signs of deficiency. The problem may persist, but this is the best solution to slow it down. If you’re like me you’ve put way too much time, planning, and energy into producing the best crop possible to have it all taken from you by some extraneous variable like humidity.

Some other additives that your plant could benefit from and work in conjunction with your calcium chloride foliar spray include:
  • Fulvic acid to enhance nutrient uptake and encourage cell elongation
  • Compost tea as a foliar will inoculate the entire plant by making it more resistant to fungal and bacterial disease
  • L-amino acids can be used to increase plant metabolism which is especially helpful during the slow metabolic stage incurred during stress
  • Enzymes work wonders when it comes to unlocking nutrients held within the root zone when applied as a foliar – kinase is the best example.
Want to learn more about stuff like fulvic, teas, aminos and enzymes?  You might like this:

|  Click HERE |


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About Frazer Love 1 Article
Frazer has been working in the greenhouse and hydroponic industry for over a decade. Currently Frazer runs his own CSA (Community Supported Agriculture) program, along with managing Flora Hydroponics in Athens, GA.

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