I just purchased a Twist and Shout ES hydrangea. I have very alkaline clay soil and would like to have blue blooms. Has anyone purchased the Color Me Blue soil prep from the Endless Summer folks and had any success? I am fearful of using the Aluminum sulphate product because of burning the roots. I also have two ES hydrandea already planted in the ground, which bloom pink. I would like to apply a "blueing" product to them. Thanks for any info.
I would definitely compare prices with other sulfur products--I think it's just sulfur and nothing special, and I would not be at all surprised to find out that they're charging more than you'd pay for garden sulfur from another source.
Sorry, I think maybe you misunderstood my comment--I wasn't steering you away from sulfur, just suggesting that you compare prices since I don't think the Color Me Blue is anything special vs other sulfur products, and I have a sneaking suspicion they will be charging more for it. Aluminum sulfate can cause more problems than sulfur since too much aluminum can be bad for plants, so if your soil is really alkaline and you need to use a larger amount of stuff to amend it down to the pH you want, sulfur is probably a better choice.
I have the bluest hydrangeas which I hope stay that way. I amended my awful clay soil with peat, coffee grounds, leaf mulch and gypsum-hoping to keep that soil acid so my hydrandeas bloom blue and stay blue. I used Epsoma Organic Traditions Soil Acidifier-which is basically sulfur! So far my Endless Summer Hydrangeas are blue, blue. Oh, I also put down a layer of pine mulch to help out!
If your soil was alkaline before, it is going to have a tendency to go back to alkaline so a one-time amendment is not going to be a long-term solution, you'll have to re-amend periodically if you want them to continue to be blue year after year.
Oh, it's definitely not something you need to do every month--I think most people do it once or maybe twice a year depending on how far off the natural pH is from the pH you want it to be. Some people don't realize that pH adjustment isn't forever, so I wanted to make sure you knew it was something you'd have to keep doing if you want blue flowers every year. If your soil was neutral or just barely alkaline and you really amended it a lot and dropped the pH significantly, you may not even have to amend every year to keep things blue, but eventually it will revert back to its natural pH so you have to keep an eye on it.