The conical heads of lime-green buds on the well-named ‘Limelight’ open to produce simply-structured, cream-white flowers with just a mere hint of pink to soften them. The heads are just heavy enough to make the branches sway, adding elegance and movement to this graceful shrub which will shine from late-July until November.
It’s one of several similar white hydrangeas and you could also grow the flat-topped H. arborescens ‘Annabelle’ or the heavier headed H. quercifolia. The latter is very good at flopping over low walls and the oak-shaped leaves also colour up to a brilliant red in September. ‘Annabelle’ is good in any border where an upright presence of cool-white is needed. More importantly it’s the most drought-tolerant hydrangea of all.
Hydrangea paniculata is very hardy native of China and Japan and it’s distinguished by cone-shaped heads of flower. Plant breeders have raised many forms and inevitably some have over large flowers on weak stems: their heads hang down very unattractively. However ‘Limelight’ is able to support its heads of open flowers well.
This plant is a new Dutch introduction also known as ‘Zwinenburg’ after its raiser Pieter Zwinenburg of Boskoop in Holland. It was bred in 1990 and its quite different from others because the conical well-filled heads are entirely made up from sterile ray florets. Limelight will reach 6 - 8 feet (roughly 2m) when fully grown.
Where to plant
All hydrangeas (except H. arborescens) need moisture retentive soil and a cool root run. ‘Limelight’ loves dappled shade and it can light up a gloomy corner half under trees. Although it has a reputation for disliking windy situations it has done well in my exposed, high Cotswold garden. I think it’s tougher than they say.
Hydrangeas also like popping up behind low walls as they enjoy shaded soil at the root.
They also make ideal container plants but do use wooden tubs. Terracotta and hydrangeas don’t get on, as the clay dries out the roots.
When it blooms
Hydrangea paniculata 'Limelight' blooms from late July until November.
When to prune
Pruning hydrangeas is often likened to pruning buddlejas which are cut down hard every spring once the worst of the weather is over. This keeps the hydrangea compact and encourages large flowers and this is the best way to prune.
But there are other options. My ‘Limelight’ has to be cut back in late autumn as it’s in the middle of my snowdrop bed. It comes through every year.
You can also reduce the stems by a third in spring and keep a bigger, leggier bush which produces earlier flowers in larger numbers - although each will be smaller in size. This tipping back technique also works with buddlejas.
White flowers can be used in two ways. They can light up shade, supported by toning plants, or they can act as a foil for vibrant colours.
If you’re using ‘Limelight’ in semi-shade the perfect partners are shade-loving plants with good green foliage which is at its best in late-summer and autumn. Ferns are ideal and the handsome fronds of Dryopteris wallichianum have darkly ribbed green leaves which highlight the pale flowers. Or you could use a variety of polypodies and polystichums to create a carpet of green ferny leaf.
If you want to highlight the colour of other plants use the late-flowering, deep-blue aconitum A. carmichaelii ‘Arendsii’ behind it or surround limelight with a vivid autumn crocus like Colchicum ‘Waterlily’ - planted about two feet away from the main stem.
Or simply grow ‘Limelight’ as a specimen plant in a strategic position in semi-shade.