Hydrangea ‘Glam Rock’ – colour changes in different soils
One of our fastest selling shrubs ever, hydrangea ‘Glam Rock’ (sometimes also known by the tongue-twister name of ‘Schloss Wackerbarth’) is a beauty to behold!
The mop-head flowers are made up of a kaleidoscope of colours, so much so that they look artificial. But the magic doesn’t end there; the appearance of your hydrangea bloom can change depending on which type of soil you have in your garden. If it has a high pH level (alkaline), the blooms will have more of the green colouring, whereas if the soil has a low pH level (acid), the blooms will be more blue.
You can see here the effects that soils containing acid or alkaline soil can give. The best way to find out the pH level of your soil is to buy a kit from your local garden centre.
Our horticultural expert, Sue Sanderson, has the following advice: “There are lots of soil testers out there that test by either chemical or electronic means, with greatly varying prices and equally varying levels of accuracy. If you just want to know what the pH level is then you should be able to pick up a small disposable kit from your local garden centre – these are fairly inexpensive. They will tell you if it is an acid, neutral or alkaline soil. These domestic kits rely on the use of a capsule that, when mixed with water and a small quantity of your soil, produces a colour that relates to a colour scale rather than a numerical value. I have used this type of kit myself and I would recommend buying more than one capsule though as it is a good idea to test from several positions across your plot instead of just one place. The more expensive kits will be able to give you N:P:K measurements as well, but remember that these will change each time you add fertilisers and soil improvers to your plot so you will need to retest the area. The more complex and expensive test kits are aimed at farmers, professionals, and garden geeks who would just want to know everything about their soil, but these are over and above the requirements (and budgets) of most gardeners.”
Did you know you can control the colour change too? Hydrangea colourant can be watered around the plant to change the pH of the soil, and therefore change the colour of the flowers!