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Bloom City Professional Grade Ultra Pure Cal-Mag Growing Fertilizer, 1/2 Pint (8 oz)

4.6 4.6 out of 5 stars 6,058 ratings
Amazon's Choice highlights highly rated, well-priced products available to ship immediately.
Amazon's Choice in Garden Fertilizers by Bloom City
$11.99 $1.50 per Ounce
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1/2 Pint (8 oz)
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Purchase options and add-ons

Brand Bloom City
Item Weight 8 Ounces
Item Form Liquid
Coverage Full
Liquid Volume 0.5 Pints

About this item

  • CONTAINS MORE MICRONUTRIENTS THAN ANY OTHER BRAND: Iron (Fe), Zinc (Zn), Boron (B), Copper (Cu), Manganese (Mn), Molybdenum (Mo), Sulfur (S)
  • BIOACTIVATED FORMULA FOR OPTIMAL NUTRIENT UPTAKE: Calcium and magnesium, Micro-chelated with fulvic acid; if you google it you’ll see why that’s good
  • PREVENTS COMMON GROWTH DEFICIENCIES: Apply Cal-Mag in every stage of growth for strong stalk and leaf health. Apply with every watering for the full benefit
  • COMPATIBLE WITH ANY NUTRIENT SYSTEM: 100% compatible with other nutrient systems, and can help make other minerals more bio-available
  • CONTAINS NO HARMFUL EDTA: Unlike other brands, Bloom City uses organic chelates and never uses chemicals like EDTA, Healthier for your garden and healtier for the planet. We choose only the highest quality ingredient sources and manufacturing methods to create the world’s best craft growing nutrient systems

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Frequently bought together

Bloom City Professional Grade Ultra Pure Cal-Mag Growing Fertilizer, 1/2 Pint (8 oz)
$11.99 ($1.50/Ounce)
Get it as soon as Tuesday, May 14
In Stock
Sold by TPS Nutrients and ships from Amazon Fulfillment.
+
Organic Liquid Seaweed and Kelp Fertilizer Supplement by Bloom City, (8 oz) Concentrated Makes 45 Gallons
$11.99 ($1.50/Ounce)
Get it as soon as Monday, May 13
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Sold by TPS Nutrients and ships from Amazon Fulfillment.
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Product details

  • Package Dimensions ‏ : ‎ 6.18 x 1.81 x 1.81 inches; 8 ounces
  • Date First Available ‏ : ‎ January 4, 2023
  • Manufacturer ‏ : ‎ Bloom City
  • ASIN ‏ : ‎ B08JHFG5GH
  • Country of Origin ‏ : ‎ USA
  • Customer Reviews:
    4.6 4.6 out of 5 stars 6,058 ratings

From the brand

Previous page
  2. Gradient Logo

    Bloom City's formulations are better for plants, people, and the planet. Our small team of botanists & plant chemists offer conscientious growers a clean and simple alternative to Big Ag fertilizers.

  3. Tomatos

    Raise Plants Healthy & Strong

    We created a line of Plant Nutrients supplements that provide essential nutrients and organic compounds plants need to grow strong.

  4. Keep It Simple & Safe

    Big fertilizer firms use harmful, outdated chemicals that are bad for people and the planet. Bloom City's nutrient systems offer craft growers a safe solution for large, clean blooms.

    We Love Big Yields

    Bloom City's unique formulas and probiotics generate high-quality yields without the low-quality, filler ingredients of other brands.

    Better For Our Plants & Our Planet

    Our sustainable fertilizers use many organic ingredients like wild Atlantic kelp, fish bone meal from the Pacific Northwest, and solar-evaporated potassium rather than industrially mined, all sourced in the USA.

  5. Organic Liquid Seaweed and Kelp Fertilizer Supplement by Bloom City
    Bloom City Professional pH Up + Down Control Kit for Balanced Plant Nutrition
    Bloom City Professional Grade Ultra Pure Cal-Mag Growing Fertilizer
    Liquid Silica Boost Fertilizer and Supplement by Bloom City

    The Plant Nutrients Series

    Visit the Store

  6. Sprouts

    Holistic Health For All Plants

    From houseplants to hydroponics, our nutrient systems have what you need for beautiful, healthy growing.

  7. Organic Earthworm Tea Concentrate and Compost and Bokashi Booster by Bloom City
    Lawn Life Super-Soil Microbes for Green Healthy Lawn Growth, Deeper Roots & Healthier Grass by Bl...
    Home Jungle - Complete Organic House Plant Fertilizer Nutrient System - Soil Myco Boost, Foliar F...
    Organic Wild Fish Fertilizer and Plant Supplement, Great for Roots and Soil, Made from Sustainabl...

    Shop All Bloom City Products

    Visit the Store

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Product Description

Product Header

Key Benefit 1

Key Benefit 2

Key Benefit 3

Key Benefit 4

Use Cases

Multiple applications for pots, garden beds and foliar spray.

Watering Can

Hose end sprayer

Application Type 3

Use in watering can for precision nutrition. Mix 2-4 mL per gallon of water during grow phase, mix 3-5 mL per gallon of water during bloom phase. Use with every watering.

Use with hose end sprayer for larger areas. Use a mixing ratio of 1:100 or 1:200, apply 1-2 times monthly.

Use as a foliar spray for rapid nutrient uptake. Mix with water at 4-8 tsp. per gallon for all stages of growth, apply once weekly.

Plant Growth Series Highlight
CAL-MAG pH Up pH Down Organic CleanKelp Silica Boost Foliar Spray
CAL-MAG pH Up pH Down Organic CleanKelp Silica Boost Organic Foliar Spray
Customer Reviews
4.6 out of 5 stars
6,058
4.6 out of 5 stars
408
4.6 out of 5 stars
1,101
4.6 out of 5 stars
4,558
4.6 out of 5 stars
1,322
4.5 out of 5 stars
493
Price $16.97 $17.99 $15.99 $19.99 $22.99 $22.99
Hero ingredient Calcium & magnesium Multiple bases for soil stability Multiple acids for soil stability Made with seven algae species Naturally sourced silica Bio-available magnesium
Primary benefit Improves plant health Optimized mineral intake Optimized mineral intake Complete plant health & resilience Stronger, larger plants More nutrient absorption
How it works Prevents mineral deficits Controls soil pH levels Controls soil pH levels Promotes root & shoot growth Strengthens cell walls Promotes photosynthesis
Why Bloom City's better More micronutrients & bio-availability Maximized bases for optimized pH control Maximized acids for optimized pH control 100% organic & naturally sourced contents Made from reacted sand & fulvic acid 100% organic & sustainable

Bloom City Values

Big Harvest, Not Big Ag

Sustainable, Natural Sourcing

Keep it Simple, Keep it Safe

Bloom City gives the power of clean, regenerative gardening to the home grower with full-spectrum plant nutrition for bountiful yields in any growing environment.

Our emphasis on environmentally responsible production methods with natural & sustainable input sourcing makes for more bio-available nutrient outputs & safer, cleaner gardens.

Bloom City's nutrient systems are everything you need to grow lush, beautiful gardens without harsh chemical fertilizers. Harness the power of regenerative growing practices to create living soil & vibrant plants.

Looking for specific info?

Customer reviews

4.6 out of 5 stars
4.6 out of 5
6,058 global ratings

Customers say

Customers like the size, performance, effect on plant, quality and ease of use of the fertilizer. For example, they mention it's large, works well in any growing method, eliminates blossom end rot and prevents rot on tomatoes and peppers. They appreciate the value, organic and the quick action.

AI-generated from the text of customer reviews

181 customers mention176 positive5 negative

Customers are satisfied with the performance of the fertilizer. They mention that it works well in any growing method, and is a great value. Some customers also say that it perked up and showed a response after one treatment.

"This Cal-Mag is easy to use, works well on my tomatoes and other veggies" Read more

"It seems to work great. I’ve grown roses that are bigger than I’ve ever grown in my life and I’ve grown fifteen foot tall trees of roses...." Read more

"No deficiencies in my garden since I started using" Read more

"This brand of cal-mag works great for me, I've been using it for over two years now and had no problems." Read more

98 customers mention98 positive0 negative

Customers find the organic fertilizer better than plant food. They say it helps keep their medicinal plants healthy and vibrant. They also say it perked up their container vegetables and improved in-ground tomatoes. Customers also say the product is wonderful for a raised garden.

"...I believe it has really helped my potted flowers bloom and grow. It is easy to use and makes a lot of liquid fertilizer for your plants." Read more

"Healthy tomato plants." Read more

"...Helps prevent nutrition deficits and adds micro nutrition your plants need." Read more

"...Where this stands apart from the others it has a long list of micronutrients that keep most deficiencies at bay...." Read more

73 customers mention69 positive4 negative

Customers find the fertilizer highly affordable and well worth the cost. They say it works quickly and is highly nourishing for transplants.

"Received order on time great price" Read more

"...Reasonably priced." Read more

"So easy to use and very economical. The results are unbelievable...." Read more

"Great value for the cost. My garden flourished using this!" Read more

55 customers mention55 positive0 negative

Customers find the fertilizer easy to use. They say it does not take a lot to work, is easy to apply, and is pleased with the quick action. They also say the directions for use are simple to follow and it goes to work pretty fast.

"This Cal-Mag is easy to use, works well on my tomatoes and other veggies" Read more

"...It is easy to use and makes a lot of liquid fertilizer for your plants." Read more

"easy to apply" Read more

"...There was no offensive odor and directions for usewas very simple to follow...." Read more

35 customers mention27 positive8 negative

Customers like the effect of the fertilizer on their plants. They say it eliminates blossom end rot, saves the yield from bottom rot and prevents rot on tomatoes and peppers. Some customers also say that it revives ailing potted cucumber plants and shows nearly immediate improvement.

"...It works miracles for blossom end rot. It seems to increase the blooms substantially, as well!" Read more

"...lots of new tomatoes coming on the vines, and most of all eliminated blossom end rot!! Thanks so much! Highly recommend. Just follow instructions." Read more

"This worked to help get rid of blossom end rot it goes to work pretty fast I mixed it in a watering pot it does not take much...." Read more

"...After useing this product the plant leaves seamed to have dried up, turned brown and the plants are dying away." Read more

28 customers mention28 positive0 negative

Customers are satisfied with the appearance of the fertilizer. They mention that their plants look beautiful, lush, and green after using it. Some customers also say that the product makes a wonderful difference in their plants.

"...and full bottle of Cal-mag, The size of the Cal-Mag bottle has a great appearance and is more than enough for anyone looking to treat certain plant..." Read more

"...Lots of blooms, lots of new tomatoes coming on the vines, and most of all eliminated blossom end rot!! Thanks so much! Highly recommend...." Read more

"...All are doing excellent, covered with flowers and the squash is covered in tiny little squashes...." Read more

"...I've been using it for a while and the leaves look a little better. But nothing to write home about...." Read more

16 customers mention16 positive0 negative

Customers are satisfied with the quality of the fertilizer. They mention that it is heavy duty, of very high quality, and will last a while. They also appreciate the strong stems and beautiful flowers. Customers also say that their tomatoes do not crack or rot and look and taste great.

"My tomatos were so healthy this year, no splits or end rot. I’ve gardened for years. This product is great. I use it on everything...." Read more

"My tomatoes do not crack, do not rot and look and taste great! So do the cucumbers and melons. Great product! Revommended!" Read more

"This product is of top quality having the micro nutrients as well...." Read more

"...You only uses a very small amount so the bottle will last a long time." Read more

16 customers mention16 positive0 negative

Customers are satisfied with the size of the fertilizer. They mention that it is large and convenient. Some say that it makes their plants grow larger and healthier. They also say that the container is large enough to last a while.

"...considerable difference in the growth of my plants, greener,healther, bigger, we havent had any rain in 26 days and my plants look great ,cant wait..." Read more

"Convenient size" Read more

"...I've gone organic and it is a nice fit with a good result. Buying again." Read more

"After I started using this my tomato plants started growing bigger and producing lots of flowers...." Read more

Bloom City Cal-Mag, A plants saving grace.
5 Stars
Bloom City Cal-Mag, A plants saving grace.
My plants were really struggling with a nutrient deficiency. I came to Amazon after looking up solutions for plant deficiency and saw this product.I ordered the Cal-Mag and received it within 2 days from placing my order.I rushed to my mail box and it was packaged nicely and secured. I opened the package and was greeted by a bright red label and full bottle of Cal-mag, The size of the Cal-Mag bottle has a great appearance and is more than enough for anyone looking to treat certain plant nutrient deficiencies.I applied the product to my plants using the recommended dosage. There was no offensive odor and directions for usewas very simple to follow.The next day I went to check to see how the plants were coming along. I was amazed and grateful to see they had started to lose the deficiency discoloration and even sprouted 1-2 more inches over night.I would recommend this product for anyone to use in their garden or growing projects.
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Top reviews from the United States

Daddydarrin
5.0 out of 5 stars Great product that ensures healthy produce
Reviewed in the United States on April 5, 2024
Size: Quart (32 oz)Verified Purchase
This Cal-Mag is easy to use, works well on my tomatoes and other veggies
2 people found this helpful
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The Architect
5.0 out of 5 stars Stuff works
Reviewed in the United States on March 9, 2024
Size: 1/2 Pint (8 oz)Verified Purchase
It seems to work great. I’ve grown roses that are bigger than I’ve ever grown in my life and I’ve grown fifteen foot tall trees of roses.
It maybe this product in conjunction with other products but it works.
I stick some diluted in a spray bottle and foliage feed the leaves both sides and it loves it.
Plus this works within three weeks per my experience.
5 people found this helpful
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James
5.0 out of 5 stars Great stuff
Reviewed in the United States on February 5, 2024
Size: Quart (32 oz)Verified Purchase
Received order on time great price
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Utah Grandma
4.0 out of 5 stars Helps Your Vegetables
Reviewed in the United States on June 23, 2023
Size: Quart (32 oz)Verified Purchase
Last year my vegetable garden did not do well. I decided to help my plants this year by giving them some help. Rge Pure Cal-Mag fertilizer has helped my zucchini and yellow neck squash to develop blooms. I am hoping it will also prevent blossom end rot on my tomatoes and peppers. I have also applied it to my garlic, raspberries, and corn as well as my in-ground and potted flowers. I believe it has really helped my potted flowers bloom and grow. It is easy to use and makes a lot of liquid fertilizer for your plants.
3 people found this helpful
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Jonathan D
5.0 out of 5 stars Works very well.
Reviewed in the United States on March 22, 2024
Size: Quart (32 oz)Verified Purchase
If you’re soil lacks calcium you will have success with this product !
One person found this helpful
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Randy L Reneau
5.0 out of 5 stars Seems to help with healthy plants.
Reviewed in the United States on April 7, 2024
Size: Quart (32 oz)Verified Purchase
Healthy tomato plants.
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jesusbuiltmyhotrod
5.0 out of 5 stars Works for foliar feed in high ph soils
Reviewed in the United States on April 3, 2024
Size: Quart (32 oz)Verified Purchase
High soil PH can lock up nutrients. Those tomatoes and squash can definitely suffer from the lack of calcium. Ironically, if you have high PH soil, you probably have a ton of calcium that is simply not available to the plants, because of soil ph.
I have always used this as directed. It works miracles for blossom end rot. It seems to increase the blooms substantially, as well!
2 people found this helpful
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R.B.
5.0 out of 5 stars Good food
Reviewed in the United States on April 21, 2024
Size: 1/2 Pint (8 oz)Verified Purchase
Keep the garden healthy
Helpful
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