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Ammonium sulfate ?

Posted by bamboo_rabbit 9A Inverness FL (My Page) on
Tue, Jun 12, 12 at 11:59

I have never used the stuff before and have a few questions that I hope Fruitnut or another can answer.

I bought a 51 pound bag of ammonium sulfate yesterday and the first question is why does it come in a 51 pound bag? There must be a reason for the odd amount. The stuff I bought is water soluble.

The bag did not say 21-0-0 on it or anything else. It is made by American plant food company if that helps. I know they add it to roundup spray tanks as it makes the round up more effective. Am I to simply take it on faith that it is 21-0-0 or is all ammonium sulfate 21-0-0 by nature?

The dose I am using is a bit low but figured to start 4 cups to 300 gallon tank to fertilize my BB. I know I could use 6 cups for the 300 gallons but being a bit cautious.

When added to my high bicarbonate water the PH stayed at 7.2 . Should I adjust the water with acid then add the ammonium sulfate or just use the ammonium sulfate without the acid?

Anything else I should know?

Follow-Up Postings:

RE: Ammonium sulfate ?

All ammonium sulfate is 21-0-0. That doesn't mean you have the real stuff but you probably do. I'd still acidify the water and only use 21-0-0 once a week at most. I fertilize about once a week when pushing growth and no more than once a month when growth is adequate.

RE: Ammonium sulfate ?


Thanks for the reply. What did you mean by "That doesn't mean you have the real stuff but you probably do". I didn't understand that. I bought the bag from Helena chemical.

RE: Ammonium sulfate ?

If the bag says ammonium sulfate and it's from Helena then I'd bet that's exactly what you have. Mine is a white, granular material. It's water soluable but takes some stirring to get it into solution. I won't expect it to lower the pH of the water. It will lower pH of the soil as the ammonium is absorbed by the plant or converted to nitrate.

RE: Ammonium sulfate ?

If your water is high in bicarbonates, it might be best to not use tap water and install some rain barrels. The solids in your water may actually buffer the pH of your soil and make it difficult to lower pH. Also, your tap water may add too much calcium to the soil which blueberries hate no matter how low the pH is. Best to just use rainwater if possible.

RE: Ammonium sulfate ?

I guess Capoman didn't read the thread about sulfuric acid.

Cap, you should search for that thread and read a few of the comments.

RE: Ammonium sulfate ?


RE: Ammonium sulfate ?

I've been using ammonium sulfate for my blueberries this year based on info from fruitnut in another thread. I only have a few bushes and have been using 1 tbsp per 5 gal water per plant per week. I've had the best results ever with my bluberries this year, and just started picking my crop this week. This is after trying a number of other things to get my blueberries to produce over the last few years with poor results.

RE: Ammonium sulfate ?

nc orchard:

Glad that is working for you. I've found that ammonium sulfate and frequent watering makes anything I've got grow like weeds on steroids. This is good for a year or two then I go in the opposite direction: water deficit and minimum fertility to sweeten fruit. Right now I'm pushing newly planted jujube to grow graft wood for next winter.

RE: Ammonium sulfate ?

Sounds like the right stuff but to be sure I would read the "guaranteed analysis" on the bag to see exactly what's in it. If there isn't anything on the bag, I would call the place where you bought it and ask them.

Although it certainly doesn't hurt to dissolve the ammounium sulf in water, you certainly don't have to. Once a month or so I sprinkle an ounce of ammonium sulf around my smaller plants and 1.5-2 ounces around the drip-line of the older plants and water it in......simple as that. I have watched the commercial farms here do the same thing with a mechanical spreader, they drive down the rows and it throws the ammonium sulf toward the dripline of the plants.

If the plants are growing well, that is you see quite a bit of new growth I wouldn't add any more....just let them grow. If you add too much fert, you can have other problems such as problems with aphids.


RE: Ammonium sulfate ?


Well I bought the AS from Helena but the manufacturer was American Plant Food. There is no guaranteed analysis on the bag. It is a white granulated product almost crystalline and it dissolves in water very easily.

Capoman, Harvestman, River


I have 142 blueberry bushes......rain water is not an option unless I install a 50,000 gallon cistern. Each time I water the bushes it is 900 gallons of water. I add sulfuric acid to the water to deal with the bicarbonates.


It was a fun thread:) Have not seen Fruitmaven/Hammilton since.


Well if I applied it dry then watered it in it would save me a lot of product. Applying it through the spray heads sure is convenient but a lot of the AS is wasted that way. Like I said there is no guaranteed analysis on the bag. The product was not intended to be used as a plant food. It is used to make spraying glyphosate more effective.

RE: Ammonium sulfate ?

Harvestman: Yes, I am quite familiar with sulfuric acid, as I use it myself. My point was that given a choice, it's best to use rainwater with blueberries rather then hard tap water that can put too much calcium in the soil. Blueberries can find calcium toxic and lock out other nutrients, even if you can get the pH down using acids. Blueberries just don't like calcium. Adding sulfuric acid to "deal with bicarbonates" does not remove them, it just counters the pH.

If rainwater is not a choice so be it, but watch out for symptoms that look like high pH or deficiency even when the pH is correct. It is likely calcium toxicity. If that happens, you may have to treat your water with RO or something similar.

RE: Ammonium sulfate ?


Adding the acid changes the bicarbonates to gypsum which is safe, stable and PH neutral in the soil and will not harm the plants at all.

RE: Ammonium sulfate ?

Bamboo_rabbit, you must not have been paying attention, I comment at least a few times a week. I imagine Hammilton isn't on anymore because he only signed up to ask questions about apple trees. Apparently, he'd just bought some land in northern WI and inherited a few. Given your reception to a newcomer, I don't blame him for not posting again.

You're so distrustful, I feel sorry for you. I'm sure your ammonium sulfate is fine. I hope your blueberries enjoy the nitrogen.

RE: Ammonium sulfate ?

I was a little curious about the calcium issue, and couldn't find evidence that blueberries "don't like calcium". On the contrary, I stumbled across a Canadian research paper that suggests the opposite.

Quote from paper:

Gypsum is a natural substance permitted for use in organic crop production in Canada. It is also a common soil amendment used to supply calcium (Ca) to the soil. Its application has been shown to increase yields in fertilized lowbush blueberry stands.

Apparently they saw the best results when gypsum was applied with a 10-10-10 fertilizer. Not that they tested a nitrogen-only fertilizer. Of course, the paper studied lowbush blueberries, I imagine it would generalize to southern blueberries.

Knock yourself out, Bamboo_rabbit. The blueberries should love it.

Here is a link that might be useful: Gypsum as an Organic Amendment in Lowbush Blueberry Production

RE: Ammonium sulfate ?

This has gypsum and is good for blueberries. It also has elemental sulfur.

RE: Ammonium sulfate ?


Seems you still have a chip on your shoulder....that is amusing. Thanks for the link though :)

RE: Ammonium sulfate ?

You're welcome.

No, no, no. Wood chips are on the GROUND, underneath the blueberries!

RE: Ammonium sulfate ?

I'd be interested in reading that study, as I've read about several books that mention calcium caused lockout issues using hard water, even when pH adjusted. Extension services often mention this problem in their releases.

That being said, for every study done, there is often others that contradict it, so my suggestion is to keep using what you have and just watch for calcium induced lockout issues, and if you get them, adjust at that point.

I experienced this issue myself with my own water, but when I replanted in a new bed, I also switched to rainwater once I had the ability to capture enough, and my blueberry plants have flourished since. What I can't say for sure is if the newly created beds improved their health, or the change in water or both. I was having issues keeping the pH down in the bed that was watered for years with well water, so I believe it was all related. In the new bed, using rainwater, maintaining pH in the soil has been a non-issue. I don't even have to correct pH in the rainwater which has a pH of 6.0, which doesn't seem to affect the soil pH.

RE: Ammonium sulfate ?

Capoman how many blueberry plants are you watering with rainwater?

RE: Ammonium sulfate ?

Certainly not the 142 bamboo has, (which was not obvious from his original post). I can understand why he would not have the capacity to use rainwater. I only have six mature highbush blueberry plants, although I am also using rainwater also for my container vegetable plants of which I have several dozen containers of 2 to 7 gallons. They also seem to grow better in rainwater. My blueberry bushes are now in raised beds, and I have several inches of mulch. Because of this I rarely have to water them anymore, even when temps hit 90+ F. When the rain barrels get low, I save it all for blueberries and water containers with tap water. I have a limited well also, and many garden and vegetable beds in sandy soil so I have to practice water conservation techniques in everything I do.

I would like to increase my storage capacity though. I only capture a small portion of the available rainwater, as it all seems to come at once. I also would like to capture more condensation from my ground source heat pump which also pumps out 10-15 gallons or more per day of what is essentially distilled water in hot weather. Currently, I'm keeping an eye out for a suitable cistern to store it all in, rather then trying to utilize and maintain several rainbarrels. I am certain that with proper mulching, and capturing much more water, that I could support a pretty large collection of blueberry plants, although that's not my style, I like to grow everything, so I only have a few of each type of plant, but in total I have somewhere between 200 and 300 plants to water. It can be a challenge in times of drought.

RE: Ammonium sulfate ?

Are all your fruit trees fertilized with Ammonium Sulfate,the same strength and frequency as the Blueberries? Brady

RE: Ammonium sulfate ?


Most of my fruit trees are fertilized little or none. And I only fertilize blueberries once a week when they are young and I want a rapid increase in plant size. I do fertilize sweetcorn 3-4 times as it's a heavy feeder and needs lots of water. For watermelon I apply 21-0-0 several times until they grow rapidly and then apply just enough to keep them growing. I try to harvest melons from the same plants from July to October so I need some growth until at least early September.

So no I never fertilize fruit trees once a week. Not even in pots where soluable fertilizers leach right out.

RE: Ammonium sulfate ?

"I like to grow everything, so I only have a few of each type of plant, but in total I have somewhere between 200 and 300 plants to water. It can be a challenge in times of drought"

Me too except I have a LOT of each type:)

142 blueberries
50 sweet Crisp
5 Gulf Coast
8 Windsor
2 southern Belle
4 millennium
14 Jewel
4 South Moon
33 Emerald
9 Sunshine Blue
1 scintilla

2 Windy (rabbiteye)
2 Beckyblue (rabbiteye)
2 Snowflake (rabbiteye)
Brightwell (rabbiteye)
Powder blue (rabbiteye)
2 Tiff blue (rabbiteye)
Austin (rabbiteye)

1 Tropic Beauty peach
1 UF Gold peach
3 UF Beauty peach trees
1 Florida Prince Peach tree
1 UFO peach tree
2 plum trees

Gulf Beauty
Gulf Rose

18 citrus trees (17 varieties)
Ambersweet orange
Taracco Blood orange
Orlando Tangelo
Mineola Tangelo
Murcott Tangerine
Meyer lemon
Ruby Red Grapefruit
Navel Orange
Dancy Tangerine
Sunburst Tangerine
Eustis Limequat
Gold Nugget

25+ pomegranates (15 varieties)(part of a University of Florida study)
Gissarskii Rozovyi
Nikitski ranni
Shirin Zigar
Russian #8
11 Vietnam (Big yellow)

5 mulberry trees

3 Fuyu persimmon trees

4 Bananas (2 types)
Ice cream
Dwarf Cavendish

100 row feet of black berry bushes (3 types, 33 feet row feet of each)

150 row feet of Mysore black raspberry bushes

50 row feet of Kiwi (3 types)

2 Dunstan chestnut trees
2 Grumichama cherry trees
3 Pineapple Guava
Cherry of the Rio Grande

11 pineapples 2 types
started from grocery store pineapple tops plus
Kona Sugarloaf

4 figs

10 20 foot rows of muscadine grapes
southern home
florida fry
Late Fry
Blue seedless
Early Fry
Li Ci

Jujube Tigerclaw

RE: Ammonium sulfate ?

Nice collection there bamboo! I wish I could grow some of the things you have such as citrus.

RE: Ammonium sulfate ?

Thats it?

RE: Ammonium sulfate ?

Other than the 200 or so bamboo yep that is it. Unless you count the 200 or so bamboo, the ducks, rabbits and quail?

RE: Ammonium sulfate ?

My friend wants to grow bamboo for a project and cut it down to harvest. Does it grow fast?

RE: Ammonium sulfate ?

Blaze, some ways bamboo is one of the fastest growing plants. It still takes a few years for the plant clump to produce full sized culms and it takes a few years before harvesting the culms does not slow the clump down.

I have been working on a 1200' hedge of it for a few years now. It started off with just 4 plants and I propagated from there and now the entire 1200' is planted (as of last fall) though will be a couple of years until it mostly fills in. That hedge is made up of probably 200-250 plants (have not counted them). Then have 10 or so other specimen types 1 of each variety.

I tend to shotgun blast lots of varieties and then just keep what I like.

RE: Ammonium sulfate ?

Blaze- If your friend is looking for slender canes, i've found that Miscanthus giganteus (grass) produced 6-8' canes with a bit of wood to them. In case you didnt need fat poles. I use them to train trees straight, as branch spacers, etc.

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