6 Best Calcium Rich Fertilizer For Tomatoes | Soil Fix That Works

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The granule blend that turns a tiny sprig into a tomato-producing tree.

This one is built for the whole season, not just a single rescue. The 5-7-3 NPK ratio (the three numbers: nitrogen, phosphorus, potassium) gives tomatoes more phosphorus for flowering and fruit set, plus a lower nitrogen level so you do not get giant leaves at the expense of fruit. It includes calcium to prevent blossom-end rot and mycorrhizal fungi (beneficial soil fungi that attach to roots) to help roots pull water and nutrients more efficiently. Buyers report that it “turned tiny cherry tomato sprig into a tomato-producing tree.”

You get 128 ounces — that is 60% more product than the 80-ounce Gypsum Granules or Calcium Nitrate options, making this the better value for a larger garden. It works for in-ground rows, raised beds, and containers. Unlike a liquid spray that fixes today’s fruit, this granular feed prevents next week’s rot by keeping calcium available in the root zone.

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The emergency spray that works through the leaf when the soil is too slow.

When you spot that first black bottom on a tomato, eggshells and soil amendments are too slow. This liquid is a foliar spray (sprayed directly onto the leaves and stems) so calcium enters the plant through the leaf cuticles within hours. Owners mention using it alongside soil-based products, noting it is “an easy and effective way to apply via the leaf/stems with little to no fuss.” One reviewer saw buds appear overnight on a pepper plant that had been dropping buds, and the rot did not return on the tomatoes.

Mix just ½ teaspoon per 11 ounces of water. The bottle is 32 fluid ounces, so one purchase makes many batches. It also reduces bloom drop (when flower buds fall off before setting fruit), giving you more tomatoes per plant. Unlike the longer-working FoxFarm or Gypsum granules, this treats the symptom immediately while you fix the soil calcium for the long term.

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High-purity calcium nitrate that dissolves fully without leaving an oily mess.

If you use drip irrigation or a hose-end sprayer, you need a water-soluble fertilizer that does not clog your equipment. This is greenhouse-grade calcium nitrate — 15.5% nitrogen and 19% calcium — with no agricultural additives that leave an oily skim on the water surface. One buyer who had blossom-end rot on zucchini and tomato plants two years running used this and reported: “It really works well! No more blossom end rot.” Another reviewer saved their bucket-grown tomatoes after 1.5 weeks of use, noting one bag goes a long way.

Because it is 100% water soluble, you can apply it as a soil drench (pour the dissolved mixture around the roots) or as a foliar spray. The resealable heavy-duty pouch makes it easy to pour what you need without spilling. It has a higher nitrogen content (15.5%) than the FoxFarm blend, so use it carefully during fruiting — too much nitrogen can push leaf growth. This is best applied early in the season when plants are building foliage and need that nitrogen alongside calcium.

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Three resealable pouches made for hydroponic systems that demand pure solubility.

This one comes as three 3-pound pouches (144 ounces total) and is specifically formulated for hydroponic and clean-water systems. Like the Cz Garden Calcium Nitrate, it is 19% calcium and 15.5% nitrogen, but ENVY markets it as “greenhouse grade” with no agricultural preservatives that leave an oily skim on the water surface. Customers note that a couple of scoops dissolved in warm water and added to nutrient solution fixed calcium deficiency symptoms (skinny stems, droopy leaves, yellow spots) and resulted in “strong leaves, better roots, no yellow spots, thicker stems.”

Each pouch includes a measuring scoop, which is convenient for precise mixing. One buyer grows tomatoes in 15-gallon pots and simply sprinkles ¾ of a scoop around each plant every few weeks. It is more expensive than the Cz Garden Calcium Nitrate, but the three-pouch set and included scoop justify the premium for hydroponic growers who need a dedicated calcium source to keep their nutrient solution balanced alongside a separate micronutrient blend.

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The pH-neutral mineral that loosens clay soil while feeding calcium.

Gypsum is calcium sulfate dihydrate — a natural mineral that does two jobs at once: it supplies calcium to prevent blossom-end rot, and it improves soil structure by loosening compacted clay so water and roots penetrate deeper. This Cz Garden version is OMRI Listed (approved for use in certified organic production) and pH neutral, so it will not raise or lower your soil’s acidity. One reviewer noted adding it to potted patio tomatoes and noted they “haven’t had any issues with the blossom end rot them since.”

It is a slow-release granular product — you mix it into the soil at planting or sprinkle it on the surface and water it in. Unlike the liquid Southern Ag or the water-soluble calcium nitrate options, this will not give you a fast fix for existing rot. But it adds sulfur alongside calcium (sulfur helps plants form proteins and enzymes), and the resealable pouch stores easily. One buyer mentioned it “just conditions my dirt” and takes time to show results, but they were satisfied with the gradual improvement.

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The 25-pound bag that feeds a serious hydroponic garden for months.

This is a water-soluble powder — not granules — designed for continuous liquid feed programs in hydroponic systems. It is part of the Jack’s 321 nutrient line and works in tandem with Jack’s 5-12-26 Part A to provide a complete nutrient profile. The mixing ratio is 8.6 ounces per 100 gallons of water to reach 100 PPM N (PPM means parts per million, a measure of nutrient concentration in the water), giving you precise control over calcium and nitrogen levels.

Buyers who use it for hydroponic vegetables say it is “hands down the best hydroponic fertilizer I have ever used” and that it makes plants “grow so quickly and produce more.” Another long-term user reported producing “amazing quality veggies and fruit.” It is a focused product for experienced growers who already know how to manage a multi-part nutrient system, not a grab-and-go bag for a backyard garden.