The Garden Community for Garden Lovers

By Guest
Who is guest?

United Kingdom Gb




The blue flower colouration is a response to the level of aluminium available to the plant, and occurs naturally under acidic soil conditions. If your soil is not naturally acidic you can:

a) grow in a large pot using ericaceous compost
b) regularly apply aluminium sulphate to the roots of the plant
c) lower the pH of the soil in the area of the plant so that it can take up the aluminium that is already available in the soil.

29 Jul, 2010


Some soilless potting mixes don't have much aluminum in them, so the aluminum sulfate is the way to go there. Sulfur pastilles and/or composted sawdust will lower the pH on those planted in the ground.

29 Jul, 2010


Or you can water Sequestrene iron tonic around the roots twice a year. Available at the garden centre in sachets, mix in a watering can.

29 Jul, 2010


Maybe there's a different formula in the UK, but the Sequestrene we have here has no effect on soil pH. It makes iron available to plants in spite of a high pH.

29 Jul, 2010


Not sure of the formula here, but what I do know is it keeps blue hydrangeas blue rather than that nasty shade of lilacy pinky "I don't know what colour to be", Tugbrethil.

29 Jul, 2010


Well, whatever its mode of action, it sounds like something I need to try. Won't know 'til spring, though.

29 Jul, 2010

How do I say thanks?

Answer question


Next question

my apple tree has brown leaves »


Not found an answer?