I have a beautiful hydrangea that was given to me by a neighbor, who grew it from a cutting of her own. Originally it was a deep pinkish-red; now the flowers are shading toward magenta to dark purple. It is growing in a mix of sand and well-composted road cuttings (got those free from when the Public Utility folks trim stuff back from the road so drivers can see better.) Quite a ways down, the soil base is sandstone and very heavy yellow clay. Are there any natural (or safe commercial) conditioners I can add to the soil to feed this hydrangea and support its pink-red color?
zannbrow, some very interesting facts came out in this old thread about aluminium in the soil affecting the colour of Hydranges flowers. This may be of interest to you. http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=41140&highlight=hydrangea+flower+colour
Yes, yes! Those were exactly what I needed! Is it already too late to change next year's flower color? Buds have started to form. Nonetheless, I will use bone meal, etc., and be patient. Eden on earth can't be grown in a day. [They also had some very helpful pruning information!] Thank you, Silver surfer!
Maybe use lime instead, the phosphorus content of bone meal can be a problem. http://docs.google.com/gview?a=v&q=...0Vb6uf&sig=AFQjCNFp3bvgRVhYa38c3uL5WmFJBbbT3A
OK, lime I can get, I think. What about Epsom salts, which I keep for my roses? Would that be acidic, or basic? I mean alkaline! I confuse the two - long time since high scool chemistry!
Epsom salt dissolved in water is only slightly acidic (pH - 6.0) and not enough to be of any use in the garden. It's used to remedy Magnesium deficiencies in soil and will not change your purple Hydrangeas to pink.