The garden flowers are either being enjoyed or getting ready to arrive now and one plant I have been asked a lot about this year is the Hydrangea. Most people like there Hydrangeas to be blue, but don’t always manage to get them that colour as they have the wrong soil type. For Hydrangeas to be blue they really need their soil to be on the acid side. An acid soil makes the metals within it more available to the plant. Hydrangeas in pots are much easier to control than in the open ground.
Turning Hydrangeas blue was one of my jobs many years ago and to do it I would make sure they were potted into a peat based compost and would water them with a blueing agent that contained aluminium sulphate. If you don’t want to use peat compost just make sure that the compost pH is lower than 7, 6.5 I find is the best. Ericaceous compost is often advised but I don’t personally like it for Hydrangeas, the soil can be as acid as you like but without Aluminium in it they won’t change colour. So, buy a good blueing agent and follow the instructions. An interesting note, the name Hydrangea comes from Greek, meaning water vessel, so whatever you do don’t let them dry out.
You hear lots of stories of people burying rusty nails and even in one case iron tablets. Yes, these things could work, but I really don’t advise it, especially the iron tablets. When putting things into the garden, you need to consider what else can be affected.
Hydrangeas are a really easy shrub to grow, just make sure you plant them where they have enough space. The most common Hydrangea is Hydrangea macrophylla and this plant can grow six feet high with the same amount of spread. Oh! Please don’t plant it in front of a window!