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Soil Acidifier

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Lower soil pH to increase nutrient intake. Alkaline soil can keep certain acid-loving plants from absorbing the nutrients they need to grow well. Blueberries require acidic soil, and so do other plants such as blue hydrangeas, cranberries, and lingonberries. This specially formulated mixture creates the perfect soil conditions for those plants to really grow. Use as directed, ideally prior to planting. One cup of soil acidifier covers one square yard of planted area. For existing plants, sprinkle soil acidifier evenly over root zone and work into soil. Contains sulfur.

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Questions & Answers

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Browse 11 questions Browse 11 questions and 40 answers
Why did you choose this?
Stark Bro's Store
I chose this because I'm growing several fruits that require an acidic soil.
Julie B on Aug 3, 2019
Have several acid loving plants that respond well to this fertilizer.
Homer B on Jul 26, 2019
I chose this because I'm growing several fruits that require an acidic soil.
Julie B on Aug 3, 2019
Soil here is alkaline
Sandra P on Aug 1, 2019
Have several acid loving plants that respond well to this fertilizer.
Homer B on Jul 26, 2019
I want the best soil for my products
Susan S on Jul 24, 2019
Not sure if our soil is acidic enough.
Laura K on Jun 21, 2019
I want to give my plants the best possible chance to grow healthy
David D on Jun 3, 2019
I bought this before and it helps increase soil acidity for my blueberries.
Easy to apply.
M M on Feb 14, 2019
To help my plants grow
Jodie N on Sep 25, 2018
Live in W. Tennessee and soil is inclined to be alkaline naturally or neutral. Know that it needs amended.
Blue berries turn yellow to remind you they need acidic soil silly fellow
JOHN W on Apr 23, 2017
a must have for blue berries
brian h on Mar 17, 2017
I have very alkaline soil so I needed to add extra to my blueberry plants, last year was my first year of a good crop now that my soil so in the right ph range.
RITA R on Feb 1, 2017
need it for my blueberries
John M on Sep 29, 2016
My lemon tree needs this.
PEGGY S on Aug 29, 2016
I understand blueberries need lower pH soil.
Rachel W on May 26, 2016
I live in a limestone area, so we need more acid for blueberries.
AMY K on May 6, 2016
I believe this is important for the plant
Louetta T on May 3, 2016
for blueberries and azaleas
James B on Apr 10, 2016
needed for blueberry and cranberry plants
Gregory C on Apr 6, 2016
I have used this for years on my blueberries; I know blueberries need an acidic environment.
MARY L on Mar 19, 2016
Better Blueberries.
Jonathan A on Mar 16, 2016
need for my 12 blueberry bushes
GEORGE R on Mar 13, 2016
Definite need for blueberries. Can be difficult to find in stores in my area.
MARY R on Mar 10, 2016
I want to give the blueberries a fighting chance. I also grown azaleas and hydrangeas so I need to keep the soil acidic.
Mary S on Mar 1, 2016
A must for proper blueberry plant maintenance.
Barbara I on Feb 25, 2016
Soil here is alkaline
Sandra P on Aug 1, 2019
I want the best soil for my products
Susan S on Jul 24, 2019
Planning to purchase both the Soil Acidifier and the 12/12/12 fertilizer. What's the best regimen to use both in the garden as to timing of applications and amounts needed per treatment?
Dave V on Mar 20, 2016
BEST ANSWER: SOil acidifier should be used the previous fall if possible. At least as early as you can. The process by which soil pH is raised or lowered takes a few months. Add lots of peat moss to your blueberry beds BC it has low pH to begin with and holds moisture..
As to applying fert, apply around drip line 6 in from base at the time of new growth in spring. Then every six weeks till mid summer.
My soil PH is 7.9-8.0, will I need extra soil acidifier to lower it to recomended levels or will the 1 cup per sq. ft. work?
Harlon H on Jul 5, 2016
BEST ANSWER: Garden sulfur lowers soil pH over time, so it's best to follow the directions and then test the soil pH again. Repeat as needed. Planting in containers is always an option while you amend the native soil.
How do you apply this to the plant? Is it to be mixed with water or do you just spread the powder around the plant?
Quinn K on Apr 1, 2016
BEST ANSWER: The directions mention to incorporate it into the soil at the time of planting. They do not specify how often this needs to be repeated or if a target pH should be achieved. I have been mixing it into and on soil around the plants, but mine are in pots.
My soil Ph is 6.0, so before planing blueberries should I till in peat moss or sulphur?
James B on Jun 27, 2017
BEST ANSWER: Both; Our soil is clay, so we mixed lots peat moss and sand into the huge holes we dug, as well as lots acidifier, as our ph is 7.5 , . in ten years, our blueberry bushes have grown taller than us, and we cannot pick all the berries :) , also, we mulch them with pine , and pull all the weeds. We usually have a lot of rain too. Blue bushes are wetland plants, which is why they require these conditions to really produce .
can I use your soil acidifier on Ruby Slippers hydrangea?
Barb B on Jul 27, 2018
BEST ANSWER: Absolutely. This can be used to amend the soil for any acid-loving plants: azaleas, camellias, hydrangeas, blueberries ...
What does lime do for soil?
Eric S on Apr 8, 2018
BEST ANSWER: Lime makes the soil "sweeter," meaning it raises the pH number to make the soil more alkaline.
Is this elemental sulfur or ammonium sulfate or something else?
Meredith H on Jan 21, 2018
BEST ANSWER: It is elemental sulfur.
Is this "acid fix" helpful for pine trees? Soil here is 8.0 pH as we live at >6000 ft.
Lois K on Mar 4, 2017
BEST ANSWER: This Soil Acidifier is beneficial to any plant that needs a lower pH, and that would include pine trees. Be sure not to rake up fallen pine needles; use them as mulch and they will help keep the soil on the acidic side. Your soil is very alkaline and will need amending for pine trees to grow.
I have fruit bearing blue berries already, is it necessary to apply soil acidifier?
arvin c on Feb 28, 2017
BEST ANSWER: The best course of action is to do an annual soil test. So many factors can alter the soil pH, and your soil may need re-acidifying from time to time. The soil test will tell you if your soil is too alkaline. Blueberries like a pH of between 4.8 to 5.5.
The directions say use 1 cup of acidier to 1 square foot of soil - is this the traditional 1 cup (8 ounces) or the cup that comes with the acidifier kit?
C K on Jun 10, 2016
BEST ANSWER: The instructions refer to an actual cup. The utensil that comes in the package is just a scoop for your convenience.

Customer Reviews

4.6 / 5.0
9 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Great for Blueberries
My new blueberry plants were not growing at all. The leaves were red. I applied the acidifier by sprinkling it on the ground each of the last 2 falls and the leaves are now green and plants are growing... a little. The better solution is to work this product into the soil when planting blueberries.
May 8, 2016
over 4 years ago
Appears to make a difference!
Our blueberries went into the ground in early spring and now are growing well and look so healthy! I read reviews prior to purchasing the plants and the additional nutrients and decided the plants needed the best start I could provide. The extra investment should prove well worth it!
May 7, 2018
over 2 years ago
Soil Acidifier
Bought this for my Blueberry Plants that I also purchased from Starks. It Works Great!
May 12, 2017
over 3 years ago
Good for desert soil.
I'm in the Arizona desert (where the soil is very alkaline), and you can easily tell the spots I've treated with this acidifier. They look so much better than the untreated things do. So I bought a heap of this stuff and have been using it since 2011.
Darryl H in Phoenix
April 24, 2017
over 4 years ago
Acidifier review
I’ve used acidifier before planting blueberry bushes. It was only enough for one application for the area that I needed it for. It worked well.
July 3, 2019
1 year ago
Cherry-Goggi berry -Wisteria
Both Goggi berry plant and the cherry tree ( self pollinating one) sprouted a week after I planted those. Very happy to see that. Wisteria is yet to show signs of life, but very hopeful. All my previous purchases were good and I do not expect my Wisteria tree to be a non- starter
May 11, 2019
1 year ago
Blueberry heaven
Soil results showed the need for the product, Looking forward to seeing how much difference this makes over the next few months. Easy to use, just need to review the results after time.
April 23, 2017
over 2 years ago
Soil Acidifier
Haven't seen results yet in lowering my 7.0 soil. Will wait a it longer, unless you think it's ok to add every couple of weeks to reduce the alkalinity of my soil. Please advise, thank you, Dianne
March 12, 2016
over 3 years ago
Response from Stark Bro's
Thank you for your feedback. It does take some time for the soil to adjust with the acidifier. Yes, you can go ahead and add every couple of weeks until you see it start to decrease.
March 13, 2016
Brenda H Staff
Perfect blend for my berries. Must have for any berry grower
May 19, 2016
over 4 years ago