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! For more great hydrangea content, head to our hydrangea hub page.
Rebecca works in the Marketing department as part of the busy web team, focusing on updating the UK news and blog pages and Thompson & Morgan’s international website. Rebecca enjoys gardening and learning about flowers and growing vegetables with her young daughter.
I contacted you on in June 2018 regarding my Glam Rock Hydrangeas advising that I had purchased then in 2015 or 2016 but never had any flowers. Graham replies to me. They always have nice bright green leaves which they still continue to loose in the winter. However this year I have a small cluster of buds on one stock. As yet it hasn’t flowered. Last year I tested the soil and it was acidic. I have also been feeding it with a Hydrangea liquid food. There’s also quite a few dry/dead stocks. Should I cut then back? Any other comments/suggestions would be welcomed.
Gosh it does sound as though your plant is taking its time to get going, but a cluster of flower buds is a really promising sign! A liquid hydrangea food is always a great start to keep your plants in good condition. Don’t overdo it though – when nutrients are constantly abundant, plants will sometimes delay flowering in order to bulk up their stems and foliage. If you are feeding twice a month, then maybe cut back to once a month for the rest of the summer.
Any old, dead or weak stems can be pruned out from the base of the plant, but don’t do this right now. Wait until autumn.
There’s lots more advice in this article https://www.thompson-morgan.com/how-to-grow-hydrangeas
All the best
Hi,I bought a Hydrangea Glam rock two years ago,it was in flower when purchased but soon after I planted it in the garden it started to change,the flowers were much smaller and dark pink only and the leaves are now half the original size and lime green,it has stayed like this now each season,it is very healthy and I actually like the way it looks but I do think people should be made aware that this can happen,I know about the acid /alcaline thing but this doesn’t usually change the whole plant ,it is unrecognisable as the plant I put in the garden.Heather.
Hello. You are absolutely right about your soil having an effect on the colour of the plant. I think many gardeners are aware of this, but it does still take some people by surprise. However, you have also picked up on the fact that many shrubs will change their growth habits when they are no longer confined to a container.
It is very common for Hydrangeas to produce smaller leaves and flowers when planted out in open ground as it is in their interests to do so. A few very large leaves will lose water far more quickly than lots of small ones – so it is essentially a survival adaptation.
Likewise, it is in the plants own interests to produce lots of smaller flowers in preference to a few very large blooms, as this increase the chances of pollination.
When plants are grown on the nursery, they are pampered. Regularly watered, fed, pruned and trained with the use of plant growth regulators to keep them compact etc. These conditions don’t exist in your garden, so the plant will gradually revert to its natural state over time.
Thanks for bringing up the question – its an interesting subject!
All the best
Hi! The leaves of my Glam Rock hydrangeas bought this year have turned very pale green. Apart from this they appear quite healthy. They are in pots of multi-purpose compost and have had one feed of slow-release fertiliser granules. Please can you advise me on how to rectify this problem? Thank you.
Leaves going pale could be a sign of magnesium deficiency, make sure the feed you’re using contains it in some form, if not, try epsom salts!
All the best
Thank you, Graham. I will give that a try.
Do they do well in full sun for most of the day? My leaves seem to be turning brown. They get plenty of water
They are quite prone to drying out very quickly. I always find that hydrangeas are the first shrub to start drooping in the garden during a dry spell, so if they are in full sun, make sure they are very, very well watered!
All the best
I have two Glam Rock Hydrangeas purchased 2 or 3 years ago as young plants from yourselves.
They die back and don’t grow very much. They have never had any flowers that I’m desperate to see. Should I put them on pots?
Sorry to hear that your plants aren’t doing so well! It sounds like they’re definitely not happy where they are at the moment so perhaps potting them up would be a good idea, that way you can try positions around your garden and see how they get on. obviously the trick is to never let the plants die out and keep them well fed too!
I hope this helps you out.
All the best
Hi Terri, we have clay ground so what would happen if I planted our Glam Rock in the clay or should we pot it if so what is the best soil to buy Thank you
Thanks for your comment, yes it should be fine to plant the Hydrangea Glam Rock in the clay soil but I would recommend plenty of compost in the area first. The PH of the soil is what has an impact on the colours of the leaves not the type of soil. See how you get on, but if it doesnt llike it then perhaps transfer to a pot. But we think you should be fine. Regards, Wendie
My Glam Rock has now flowered for its second year.
Last year it had three flower heads which were pink and went darker red as it aged but it showed none of the colour variation I expected.
This year there are about twenty flower heads but they are all quite a plain pink, the small flowers in the centre are tiny and (if anything) white.
The flowers have never looked anything remotely like the catalogue photos.
Am I doing something wrong? The plant is in a container of multi-purpose compost plus an initial feed of chicken manure. I occasionally feed with liquid food and have also experimented with Vitax colourant for the past four weeks (no difference). Photo available.
Hi Tim, from personal experience the best colour variations tend to occur in a more ericaceous soil. It would be worth repotting in the autumn, into a mix of ericaceous and John Innes No.3. I would also suggest feeding with an ericaceous fertiliser and continue with the colourant. Colourant is really a long term project and will take some time to have any effect. Also, try to water with rainwater as the lime which is present in tap water will turn the soil alkaline over time. Hope that helps, Terri
Dear Rebecca – I have 2 Glam Rock Hydrangea which are now 3 years old (purchased from you in Nov.12). They are planted in containers on the patio in full sun. They have really taken off this year with an abundance of flowers. Last year the heads were pink/green but unfortunately they are just deep pink this year. The same appears to have occurred as Marion’s above. Any suggestions please.
From personal experience the best colour variations tend to occur in a more ericaceous soil. It would be worth repotting in the autumn, into a mix of ericaceous and John Innes No.3. I would also suggest feeding with an ericaceous fertiliser and continue with the colourant. Colourant is really a long term project and will take some time to have any effect. Also, try to water with rainwater as the lime which is present in tap water will turn the soil alkaline over time.
I have an Hydrangea Glam Rock purchased from your sister company over a year ago. It is fairly well established in its pot and I used the appropriate compost to plant it, as all those I put in my garden always go pink regardless of how they look when I buy them! Unfortunately despite my efforts I only got the green/pink flowers last year. Please do you have any suggestions. It was not cheap and bought especially for the flowers it promised. I see it is budding now again. Thanks in anticipation.
Hi Marion, thank you for your comment. We have sent you our response via email. Best wishes, Terri
My Glam Rock are in flower again for the second year and look great but are green/pink with no blue. Is there anything I can add to the soil which might add some blue tinges for next year?
Hi Richard. The blue shade of Glam Rock come out best when plants are grown in acidic soil. Whether you are growing in containers or in the ground, you can raise the acidity by applying Vitax Hydrangea Colourant around the base of the plant and watering in. This is available on line and at most garden centres. Hope that helps 🙂 Terri
can you please tell me how long the glam rock hydranger takes to mature. being as they are very small plants when purchased.
Hello, ‘Glam Rock’ will take about 12 months to mature. I hope this helps. Best wishes, Rebecca
I have a “Glam Rock” which is now just 1 year with me. I was a little disappointed last year as all I had was foliage. WOW, this year I have so many clusters of blooms just waiting to open. I am so delighted and excited for them to open, I really can’t wait.
Dear Rebecca, we started our own campaign to support the British economy by raising the profile of products, foods and services that support British £’s in British tills. Our research has led us to some very upsetting finds. As a member of the public, I was most upset to discover that we have lost over 80% of our British flower growers.
As someone who adores flowers and indoor plants, I think there should be a campaign to bring British flower trends to our homes.
Over the last few years our homes have been filled with Orchids as interior designers, hotels and luxury homes have made them the “on trend” plant.
We have found farmers talk to farmers, flowers growers talk to flower growers and so on! Our site is shared with all industries, so we reach a wider audience!
It would be great if we could get British flowers back on trend in our homes. Love to hear your views!
Hi Jayne, thanks for your comment. We also agree that it’s important to support British growers and many of our plants feature the ‘Home Grown’ mark. However, it’s also important to remember that British growers face fierce competition from abroad and while plants grown here are of better quality, not least because they’ve travelled fewer miles, they are more expensive because of our high fuel costs for transport and heating. The hope is that, as the demand for home-grown products increases, more will be offered in the future. Best wishes, Rebecca