I think we need some information before we can provide any help. Where are you? (you might want to add this to your profile so we don't have to ask.) Have you had a soil test done to know what your pH is? The flower color is a combination of the variety you have (some have naturally more intense color), the soil pH, and whether there is aluminum in your soil (which having an acid pH makes available to the plants.). How many plants do you have? What jugs are you talking about? Is your soil pH acid? Have you done a search here on the hydrangeas forum or on website of a hydrangea specialist rather than the randomness of information value which one gets with just googling? Choosing your information source is important, and we don't know where you found info, and therefore how reliable or not it was. If you give us more info, you may get more help.

For me, I have acid soil with available aluminum, so I do nothing for my hydrangeas other than mulching them well with shredded organic material. My shrubs bloomed pink while their roots were still in the original potting soil, but have been blue since their second summer.

Babs has summed it up very well. We really need a lot more information before we can make any specific suggestions.

I would also state that only macrophyllas and serratas produce flowers whose color can be influenced by soil conditions. And not even all of those :-) White flowers will always be white (until they develop any age related coloring) and some other cultivars will produce very stable coloring that does not respond easily, if at all, to soil pH.

The simplest way is to first determine what is your soil pH and, if alkaline, try amending with aluminum sulfate one shrub that has been potted (it is harder to do this when planted in the ground). And follow the label instructions (how much in how much water and apply how often) as these can vary. Continue doing that "forever" because if you stop amending the soil, it will revert back to its original alkaline state.

Try getting bags of spent coffee grounds FREE from local coffee shops. Should help a little, because they'll help turn the soil toward the acidic side. That's assuming the soil's alkaline to begin with.

Places like Starbucks sometimes set out spent bags up to 10 lbs in size. Apply immediately as letting the bags sit will get moldy.

Used coffee grounds are not at all effective for altering soil pH. The bulk of the acidity is in the coffee liquid itself - spent grounds (UCG's) are pretty close to neutral or just slightly acidic on the pH scale and you would need truckloads of them to alter pH to any significant degree. Starbuck's coffee grounds lab test

A better method and the one most often recommended to increase soil acidity is to amend with sulfur.

Yes, I agree. I was surprised when I started getting coffee grounds from Starbucks that they had notes saying that there would be little minerals left after boiling to make much of a difference. But I still use them as my dogs love getting all "dirty" in the coffee grounds!!! When they come back into the house spreading coffee smell, I know where they have been. The most ph affected is probably a tiny, tiny soil layer in the top soil... and not by that much. Useful in the winter since it has 2% nitrogen (so just a tad) plus many secondary minerals.

So what you're saying is UCG's won't make the raccoons stop digging up all my mulch on a nightly basis while looking for nightcrawlers? ;)

No, what I'm saying is that applying UCG's will do very little in the way of acidifying the soil. And since they are organic matter that will stimulate the soil biology as it breaks down and decomposes, they could very well encourage incursion by raccoons, as the populations of worms/night crawlers will probably increase.

thanks for the comments, ive been busy lately but I am in coastal SC, zone 8b. I have not had a soil test, which is what I forgot to add to.. I had noticed there are two types of soil tests.. One where you gather 8 or so samples in the yard to combine and send away. Or I also saw this soil acidity prong meter ?? You just poke it in the ground and it tell you what your ph is ? Is that actually reliable, and any recommendations on which brand is better. I know I will need to know ph first.

I have about 15 plants right now, maybe a few more this fall if I can find the right variety. I have a high morning shade and bright afternoon sun spot that I cant find a good white variety for. The jugs I was referring to are the Endless Summer jugs they sell. They make their own amendment that you can spread out and buy either the pink or the blue versions, they are just expensive when you have so may plants like I do. I can say what I found online was probably not that reliable, it was just chatter between people on different message boards. It was not very specific to my area or needs, which is why I wasn't getting anywhere and started this.

hope that gets me started

pH meters or probes tend to be extremely inaccurate unless you purchase an expensive model and recalibrate with each use. The pH test kits you can purchase at most nurseries (even box stores) are actually quite accurate for the money IF you use distilled water. Tap water can throw off your results. Don't know about SC but many states' extension service will do a basic soil test very inexpensively and that will provide a nutrient breakdown as well as pH. That may be helpful as it should break out the Al concentration.

I wouldn't bother with the amendment 'jugs' sold by ES. They are guaranteed to be more expensive than what you can purchase off the shelf and likely the same products. Apply lime if you want pink flowers - sulfur and/or aluminum sulfate if you want blue. Knowing the pH will help you determine which and how much.

Ok great, I will call a nursery and ask. I only saw my extension service had it ,but it wasn't cheap. ill get that info and them let you all know.

how about this kit ? Should it be ok, or would the single ph tester be all I need ?

https://www.amazon.com/Luster-Leaf-Rapitest-Tester-1609CS/dp/B0019AI7PU/ref=sr_1_10?ie=UTF8&qid=1500309376&sr=8-10&keywords=ph+soil+test

or

https://www.amazon.com/Luster-Leaf-1612-Rapitest-Tester/dp/B0001LEPYA/ref=sr_1_4?ie=UTF8&qid=1500309376&sr=8-4&keywords=ph+soil+test

Go with the second ;-) While the home test kits for pH are reasonably accurate using distilled water, the nutrient tests are usually way off. Save yourself a buck or two :-))

deal ! This kit comes with 10 "tests", do I need to test the soil around each plant or just in each general area ? I have three areas, one area with 7, one area with 3 and one area with 5 plants