Hydrangea Macrophylla “Ab Green Shadow”
A complete guide to this compact, beautiful Hydrangea
By Daniel Woodley at DIY Gardening
Hydrangeas are one of the easiest plants to grow, and “Ab Green Shadow” is my favourite, so much so that I have two in pots and another one in a border.
Of note are the flowers, which start a lime green colour but gradually transform to pinkish-red with the edges of the petals changing colour first.
This compact Hydrangea is perfect for pots and smaller gardens, is easy to propagate, maintain and is generally pest and disease-free.
Below you’ll find everything you need to know about “Ab Green Shadow” and for more general advice on hydrangeas, check out our Ultimate Guide to Growing Hydrangeas.
Hydrangea Macrophylla “Ab Green Shadow” Photos
Here are a few photos of this plant growing in my garden, you are welcome to share or use these images on social media, your blog or website etc, just provide attribution by way of a clickable link back to diygardening.co.uk:
Plant Guide – Key Points
Here is an overview of Macrophylla “Ab Green Shadow”.
More in-depth information and answers to common questions can be found further down the page.
Moisture and Feed:
Pests and Disease:
Planting Hydrangea “Ab Green Shadow”
As with most hydrangea macrophylla shrubs, choose a location that provides some sunlight but also protection from blistering midday sun. This protection is even more important if the shrub is grown in a container as the soil is more likely to dry out.
Dappled shade, partial sun or even a spot that receives plenty of morning and evening sun will be fine provided there’s some shelter during the hottest time of the day.
Hydrangeas prefer moist soil, so elevated positions in raised borders or pots may cause the soil to dry out, and more frequent watering may be required in the summer.
While this macrophylla “ab green shadow” will thrive under filtered light through overhanging tree branches, avoid planting too close to the roots of large trees as competition for water will be fiercest here.
Most hydrangeas prefer space from other plants, so avoid overcrowding the base of the shrub if possible.
Water and Fertiliser
While this hydrangea prefers moist soil, it should never be left in waterlogged soil, so containers should have drainage holes.
There’s no need to water this shrub daily unless it’s very hot and dry outside. However, do test the soil with a finger every day or so during heatwaves and provide water as required. If you aren’t watering frequently enough, your hydrangea will let you know, and leaf sag is the first sign to look out for. Waterlogged roots or overwatering can lead to leaf yellowing, often affecting new leaves rather than old, established leaves.
Apply a good layer of fresh compost in the spring and specialist hydrangea feed fertiliser two or three times in the summer for optimal growth. There is no need to fertilise more frequently than this.
These slow-release granules from Vitax provide all the nutrients hydrangeas need. Check prices online here.
Pruning This Hydrangea Macrophylla
“Ab Green Shadow” is a compact shrub that will grow up to one metre high and is unlikely to appear leggy and sparse unless seriously neglected and it probably won’t need much pruning.
As with all macrophylla hydrangeas, you can leave the flowers on rather than deadheading as they will offer frost protection for next year’s buds during the winter.
When the risk of frost has passed in the spring, cut off the old flower heads to the first bud below the old flower, you can prune down to the second or third bud to maintain shape, but be aware that this hydrangea will only produce flowers on stems that grew previously (i.e. old wood), so avoid aggressive pruning of this growth.
To prevent this macrophylla from becoming leggy and sparse and to maintain its compact shape, you can (optionally) completely remove a few stems each year by cutting them off at ground level; this encourages new growth that will bulk out the centre of the shrub.
There is no set rule for how many stems should be trimmed close to ground level, but here’s a rough guide:
- New plant, less than three years old – None.
- Typical plant that requires yearly pruning – remove between 0-20% of the stems at ground level. Bear in mind that this hydrangea doesn’t require yearly pruning so only prune to keep the plant’s growth under control and to maintain shape.
- Overgrown plant – cut off half of the stems so the other half still produce flowers this year, then repeat the process and cut off the remaining 50% next spring.
- Seriously neglected hydrangea plants that are very leggy and sparse – cut off all the stems just above ground level. This hydrangea will recover from such aggressive pruning but won’t produce flowers until next year.
An alternative way to prune hydrangeas is to do so after flowering in the summer but before the shrub sets new buds.
Our guide to pruning hydrangeas contains everything you need to know about this task.
As with any macrophylla, frost may damage the emerging buds in the winter.
There are a few ways to prevent this:
- Don’t deadhead the flowers; leave them on until the spring as they provide protection from frost.
- Cover plants with fleece when frost is forecast.
- Water before frost as it offers protection.
- Remove frost-damaged buds to the next set of healthy buds.
This hydrangea should recover and still produce flowers after mild frost damage to the tips of the stems and buds, but the more protection you can provide, the more flowers it will produce.
Pests and Diseases
Hydrangeas made it onto our list of plants that slugs won’t eat, and the good news is that many other pests also stay away from these shrubs, and diseases are rarely an issue either.
Watch out for:
Leaf Spot is a reddish-brown fungus infection that can affect all hydrangeas and looks like harmless autumn colour changes. Our guide to hydrangea leaf spots can help you diagnose and treat this disease.
Powdery Mildew is also an issue for some shrubs. Adequate plant spacing and prompt removal and disposal of infected leaves can reduce the effects – more details here.
Aphids affect hydrangeas but rarely kill the plant and can be treated with sprays purchased from garden centres or these sticky traps. Curled leaves are a tell-tale sign of aphid infestation, so check the underside of the leaf and treat it as required.
How to Propagate Hydrangea Macrophylla
I was so impressed by “Ab Green Shadow” that I’ve taken cuttings twice and both times I’ve had a very good success rate.
I only wanted one shrub for my border (I already had two ab green shadows in pots), but I assumed that at least one would survive if I took four cuttings.
I was pleasantly surprised when all four survived, even though I took the cuttings late in the season. The only equipment I used was an empty plastic drink bottle and a heat mat for 3 weeks.
Here are a few photos:
This is my favourite hydrangea at the moment, and it’s been easy to grow with very few issues. In fact, the only problem I’ve witnessed was some yellowing of the leaves on a friend’s specimen, which was easily fixed.
Hydrangea macrophylla shrubs are perfect for beginners and the “ab green shadow” is ideal for smaller gardens and containers.
I do have one gripe that I feel is worth sharing with you – hydrangeas do absolutely nothing for the environment. Birds, bees and butterflies do no benefit from hydrangeas at all; thus this shrub should be seen as purely ornamental, it does nothing for wildlife (except a few aphids!).
If you would like to know more about plants that help wildlife, check out our guide to helping the bee population.
More From Daniel Woodley:
This guide to growing hydrangea macrophylla “ab green shadow” was created by Daniel Woodley, is part of our ultimate guide to growing hydrangeas and was last updated in August 2021.
Daniel is a keen amateur gardener who also manages a large residential landscape and his own mid-size garden. He also enjoys growing vegetables and fruits, as well as his herbaceous border and container garden.
You can follow Daniel and Hannah via DIY Gardening’s blog, where you’ll find a ton of exciting content.
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