skip to main content

Hydrangeas garden

Overdose aluminum sulfate

25 days ago

Hello!

I applied aluminum sulfate to my hydrangeas in hopes that they would bloom blue but I misread the instructiins and put way too much… about teo general handfuls around each plant that I then watered in. is there any way that I can help to mitigate the damage?? maybe flushing them with water might help??

Sort by:Oldest

Comments (6)

gardengal48 (PNW Z8/9)
25 days ago
Was that two (2) handfuls of aluminum sulfate applied per plant? If so, that may not be too much. The recommendation is 1 cup of a 15% concentration of AS for a 4' hydrangea, although it is generally applied in a couple of applications rather than all at once. If you think you applied too heavily, flushing the plant well with water can help.

FWIW, I would have thought your soil pH in CT acidic enough to produce blue flowered macs without having to resort to AS. Not so?
Susan , 7a, CT
Original Author
25 days ago
Hi there,

Thank you for your reply and insight! Yes, it was 2 handfuls per plant… and they are about 3’ tall. For all they say about new england being perfect for blue hydrangeas, that doesn’t seem to be the case with mine! I think perhaps it has to do with the cement foundation of the house as I end up with mostly pink and purples. I am a new gardener and have been so eager (and impatient) to get my hands in everything and so I made this mistake in a rush today. I will try flushing it well with water and hope for the best!!
Related Discussions
Aluminum Sulfate for Blueberries
Q
Comments (26)
I think I may have OVER sulfured my blueberries this Weekend, but I am not even sure I obtained the right Product When I stopped by my AG Supply store on my way to my plantings this weekend and asked for sulfur the provided a 50 LB bag of sulfer as a wettable powder, when I asked how much to use on my bushes most of which are about 3 foot and fairly well bushed, He stated about 4 cups spread around each bush, My plantings are not at my residence, and I had no manner to check here to elsewhere and I applied that amount to each this weekend, that was followed by a pretty heavy rain. It spoke of above on "burn" Is it like a nitrogen burn, and is sulfur a N value, as I know blueberries do not like heavy N , I will not be able to check on them for 2 weeks should I expect damage from 4 cups of this product listed below, I really have concern this morning on reading this and other posts. http://www.georgiagulfsulfur.com/images/ISIEM70.pdf SECTION 1 CHEMICAL IDENTITY Trade Name & Synonyms: Yellow Jacket Flowable Sulphur, EM 70 Chemical Name: Sulfur Family Name: Element - Sulfur Chemical Formula: S8 Appearance: Creamy pale yellow liquid CAS Number: 7704-34-9 Hazardous Ingredient: Sulphur % by Weight: Flowable Sulfur 53%, Fluid Sulfur 70% SECTION 2 PHYSICAL DATA Appearance: Creamy pale yellow liquid Odor: Sulphur odor, or faint odor of rotten eggs Purity: 52%, 70% Formula: S8 (Rhombic or monoclinic) Vapor Pressure: Solid: 0.0001 atm Liquid: 0.0014 atm Solubility In Water: Disperses to form an emulsion Specific Gravity: 1.30, 1.5 Boiling Point: Not available Freezing/Melting Point: Not applicable Bulk Density: 11.4 lbs. / gallon, 12.9 / gallon
...See More
Where to buy aluminum sulfate?
Q
Comments (3)
Naturally acidic soils are common here on much of the west coast and aluminum sulfate is readily available at any nursery as well as all the box stores and other places that carry plant fertilizers and amendments. I'd be cautious about using alum as a substitute - there are many formulations of alum and their chemical characteristics are not the same. Plus, it would be difficult to tell if you are applying enough or overapplying since it doesn't come with any directions for use in the garden. Agricultural sulfur is useful for acidifying soil but if you do not have aluminum present in sufficient levels, it will not help to turn hydrangeas blue - it the access to aluminum that makes hydrangeas blue.
...See More
How much Aluminum Sulfate for Endless Summer Hydrangeas
Q
Comments (2)
Good morning, mercime. Aluminum sulfate comes in several forms (powder, etc) and in several concentrations so a single formula will not work for all versions sold out there. I hate it when they give me weight requirements like that (because I have no scales of any type) so, what I do is determine how many pounds I will need as a percentage of the package's weight and take out that much. So if I need to apply 1 pound and the package weighs 4 pounds, I extract 1/4 of the package's content. Because less is more when dealing with compounds that have Sulphur, feel free to use less anytime. Because my soil contains naturally occuring aluminum but is alkaline, I always have to apply something in Spring and sometimes again in the Fall. My bag of a/s is now empty since last Fall and I am just using Garden Sulphur. If your soil has adequate amounts of aluminum, you can do the same; otherwise stick with a/s. You can also use iron-chelated compounds or greensand if you are into organic stuff.
...See More
When to apply aluminum sulfate to change the color
Q
Comments (2)
Amending the soil to change the color takes a long time and once you start, you need to continue forever or else the soil will slowly revert back to its pre-amendment levels. Starting a couple of months before the plant leaf -ed out might be ok but it varies depending on how alkaline your soil is and what amendment you are using. Try getting some aluminum sulfate and apply it from now on according to the label's directions (not more). Continue applying per label directions thru the whole year but temporarily stop if the soil freezes in winter where you live.
...See More
gardengal48 (PNW Z8/9)
25 days ago
Ah yes - proximity to concrete could cause problems with the bluing :-) But I honestly don't think you have done any damage. Unless you have very big hands, two handfuls is barely going to make a cup, so you should be good.
Susan , 7a, CT
Original Author
25 days ago
Thank you so much, I feel so relieved to hear this from you! I am hoping gardening will teach me how to be more patient and thoughtful going forward!! 🙃 Many thanks again!
luis_pr
25 days ago
last modified: 25 days ago
I accidentally dropped too much when my dogs were playing with each other as I was about to drop a/s into the ground. I just picked it up and applied it elsewhere. And watered well. Just pick up the excess and apply it to another plant or add it back into the a/s bag. I did make a few soil tests after 2 or 4 weeks later with my soil pH kit just to ensure the pH was not off the charts. Not a terribly accurate unit but enough to calm me down. You can monitor the plants too to see if they react.
Susan , 7a, CT
Original Author
25 days ago
Thanks, Luis! I feel much better knowing all of this. I was so panicked yesterday. I tried scooping some sugar with my hands last night and it turns out that is only 1/8 cup 😂 Phew!

Related Stories

GREEN BUILDING Ecofriendly Cool: Insulate With Wool, Cork, Old Denim and More

By Julia Pockett

Learn about the pros and cons of healthier alternatives to fiberglass and foam, and when to consider an insulation switch

HOUSEKEEPING How to Clean Hardwood Floors

By Bonnie McCarthy

Gleaming wood floors are a thing of beauty. Find out how to keep them that way

HOUSEKEEPING It’s Time to Clean Your Gutters — Here’s How

By Bonnie McCarthy

Follow these steps to care for your gutters so they can continue to protect your house

LANDSCAPE DESIGN 9 Ways to Bring Pantone’s Classic Blue Outside

By Lauren Dunec Hoang

See how the 2020 Color of the Year can help create serenity and add timeless style to a patio or garden

HOUSEKEEPING 7 Chores You May Be Doing Wrong

By Pauline Morrissey

Find out the best way to clean glass and change a duvet cover — and why you should remember to look up

KITCHEN DESIGN Kitchen Sinks: Antibacterial Copper Gives Kitchens a Gleam

By Rachel Grace

If you want a classic sink material that rejects bacteria, babies your dishes and develops a patina, copper is for you

GARDENING AND LANDSCAPING Porch Life: Banish the Bugs

By Becky Harris

Don't let insects be the bane of your sweet tea and swing time. These screening and product ideas will help keep bugs at bay on the porch

HOUSEKEEPING How to Clean a Glass Shower Door

By Bonnie McCarthy

See which tools and methods will keep those glass shower walls and doors sparkling clean

GARDENING GUIDES 10 Ideas for an Exuberantly Abundant Landscape

By Debra Prinzing

Let passion and largesse overflow for a garden that provides a rich experience along with a beautiful scene

GARDENING GUIDES Summer Gardens Sing With Blues

When hot weather hits, bursts of blue keep the garden palette cool and calm

Sponsored

More Discussions

Need info on Hydrangea Delft Blue

5

When to add fertilizer? Zone 6b

3

Hydrangea bobo vs. hydrangea little hottile.

2

What are your favorite companion plants for hydrangeas?

0

Hydrangea (winter die back)

3