How do i keep my hydranges blue

The blue colour indicates acidic soil. Using the pH scale of 0-14, acidic falls between 0-7, and alkaline (lime, chalk, eg) in 7-14. hydrangeas are, therefore, a useful guide to your soil pH. it is far easier to change the flower colour from pink to blue than from blue to pink (white ones cannot be altered, so far as I know). The key trace element is aluminium. A traditional method, taught me by my dad, is to bury a pile of rusty nails among the roots. A proprietary liquid feed is also now available for this purpose, but needs continuous adding. Best bet, if your soil is not acidic, is to keep your blue hydrangea in a container, use ericaceous compost (as for dwarf rhododendrons, blueberries, and suchlike), and re-pot in this medium as the plant grows, and top up the compost each Spring. With regard to watering, try to use collected rainwater whenever possible, as this is more acidic than tapwater. This may sound like a whole lot of bother, but is actually not at all. I have grown this, blueberries and rhodos this way for years, and it is now so "routine". Hope you find this useful. :-)

Or you can buy Sequestrene Iron tonic and water that round the base a couple of times a year.

That was exactly what I was just searching after! Many Thanks, Bamboo! :-)

When I was a kid we had a pet guinea pig. When he died after several happy years we buried him under a pink hydrangea and that side of the bush gradually turned blue. I'm not making any suggestions though.....

Lol, Beattie - somewhere to put my husband I suppose... by the way folks, coffee grounds are acidic, you can always dispose of those round the bottom of the bush too.