Blue hydrangeas. Sort of.

hydrangeaI love blue hydrangeas. They’re gorgeous… er, when they’re blue.

But keeping them blue is a bugger. I have neutral soil, so it’s extra hard. But even if you grow them in a pot of ericaceous compost, you have to shovel in absurd quantities of aluminium sulphate – regularly – to stop them reverting to pink.

I’m failing with this one. There’s been so much rain [soilman.net 2012, passim] that the colorant is leached out of the pot almost as fast as I can pour it in.

Anyone got any tips for keeping ’em reliably blue?

PS I’m beginning to fear the corn will fail this year. It’s SO fucking cold and wet that it’s put on pathetic growth. I can’t see it having time to fully grow, flower and form ears before the frosts.

2 Responses to “Blue hydrangeas. Sort of.”

  1. Tanya Walton Says:

    Why don’t you just leave it be?? I’m not one for messing with things just because I want it to be different!!!

    Hope the weather warms up so we can have some corn…not sure I can cope without it. 🙁

  2. Judith Adam Says:

    Hello Soilman,

    I enjoy reading your blog; and often, I share your horticultural anger.

    My grandmother’s hydrangeas were always blue (okay, some were blue lurching to purple as a bit of pink seeped in), because her soil was acid, probably just under 6.0 pH. That’s really the only way to do it, to grow them in naturally acidic soil in the 5.5 to 6.0 pH range. Otherwise, all the manipulations (aluminum, compost, fish heads) will only frustrate your desire for lasting blue.

    Here’s the thing — purchase blue hydrangeas in pots when they’re offered at Easter (as they are here, on this side of the pond) and enjoy them for two wonderful weeks. (Get yourself photographed with them!) And otherwise, grow a collection of gentians. I can say that gentians go a long way toward satisfying the blue urge.

    Fight on!

    — Judith Adam