I have read several things in past forums about needing aluminum in the soil to make it acidic enough to keep the blooms blue. What specifically can I add to the soil? Will peat moss do the job?
How can I make my blue hydrangeas stay blue?
I know this is not going to give you the information you need, but I suggest you get a soil test in the area where you plant your hydrangeas. To have blue flowers, you must have acidic soil. Here in central Alabama, people often plant hydrangeas among pine trees. Pine straw, over a period of time, increases the acidic content of the soil, which makes the aluminum in the soil available to the hydrangea. You can increase the acidic level in your soil by adding garden sulfer. It can be purchased at Lowe's or similar places, but please be careful. A little bit goes a long way, and it stays in the soil for a very long time. Peat helps, but it is a slow process, and the greatest weakness of many of us gardeners is that we want the TV sitcom solution. Peat moss will not offer that solution. I grow many hydrangeas, and the blue flowers are in the same beds as my azaleas and rhododenrons. I'm not a dogmatic gardener. Try what you think will work, and don't worry about what the other gardeners think.
Thank you so much for your reply! I think I will gradually try to change the soil. My hydrangea flowers are actual quite gorgeous right now - since they are blue and turning slowly to pink, they are almost purple!!
That's the way most of my Hydrangeas are. I don't try to make them blue. I love their varied colors. In all honesty, I don't get the blue thing. But, to show my inconsistency, I do love blue gardenias. Sorry, my wife and I are still old Nat King Cole fans. lol. Happy gardening.
Read this
http://davesgarden.com/forums/t/602059/
ok, explain the "blue gardenia" reference. How do you do that?
You can buy aluminum sulfate at Lowes to make the soil more acidic, making them blue. The AS I bought is 2 TB per gallon of water, I feed them 3 times during the spring, before the buds start to show.
To make them pink... dolomite lime, (think I spelled that right). I have no idea where you get that, I know Lowes by me doesn't carry it.
Thanks isThis Heaven, By the way, our Lowes does carry dolomitic lime, so if the soil is acidic, people apply it to the soil around the Hydrangea. It is far less risky than garden sulfur or aluminum sulfate. You don't get blue, but you get a range of beautiful blooms. The gardenias will also benefit from iron. Some folk use Miracid. We gardeners spend a great deal of effort in changing what we naturally have. I guess that's what gardening is.
ok, I know about changing the color of hydrangeas, but I thought they meant we could change gardenias! That was new to me.
Changing the gardenia blooms to blue takes a bit of time, but they are neat when you get there.
My soil and irrigation water is so alkaline that I had to up the aluminum treatment to half a cup in order to get blue flowers.
I learned along the way, I also prefer the purple in between color.
Siggy
Is that a half of a cup per gal? How long did it take to make the change in color.
Gary
I planted a Nikko Blue next to a pine bush, it gets blue flowers every year, no fooling around with the soil. Planted more hydrangeas all over, different varieties, not necessarily next to pines, exciting to see what they will be. So far only Amethyst (of what I planted this spring) has bloomed, and it is amethyst. I'd heard somewhere that pine needles can acidify soil gently.