Thanks to the UK’s increasingly hot summers, the RHS is considering relocating its Wisley hydrangeas to its northern Gardens. It’s a concerning move for hydrangea lovers in the south – but that doesn’t mean we should give up on our plants.
When you’re deciding where to plant hydrangeas, it’s always worth remembering that they’re woodland plants by nature, and they thrive in light shade. That means heatwaves and droughts are tricky conditions for the shrubs – but does that mean they’re no longer suitable for southern gardens?
Luckily, the answer is no. We spoke to RHS chief horticultural advisor Guy Barter to find out which varieties are most likely to thrive in southern gardens – and how to save the hydrangeas we already have.
This summer’s been a scorcher, and although there are ways to look after hydrangeas in a heatwave, I’ve spotted a lot of brown plants lately.
It makes sense, then, that the UK’s leading gardening charity is thinking about rehoming its RHS Wisley hydrangea collections in the north. We asked Guy about what’s motivating the move.
‘RHS Wisley is a very dry area,’ Guy said. ‘It’s got very dry, sandy soil, so some hydrangea varieties in some parts of the garden can be under pressure in hot, dry weather. Rather than giving ourselves a lot of work to keep them watered and cared for, we’re thinking about relocating them to our northern gardens, where it’s moister, the soil is more water-retentive, and they’ll need less looking after.’
It’s no secret that hydrangeas are perfect for damp gardens, and that’s where they’ll put on their best displays. That’s why RHS Wisley is going to keep some hydrangeas on its north-facing slopes, for example – and you might already be growing your plants in similar conditions.
‘In many cases, hydrangeas will be growing in quite clay soil,’ said Guy. ‘They’ll be growing on north-facing slopes in light shade, perhaps from the house or a wall, so they’ll be in good condition already.’
Some species perform better in hot, dry conditions though.
‘Hydrangea paniculata is a little bit tougher than the mopheads and lacecaps, and that’s one of the ones we use a lot at Wisley,’ said Guy.
Hydrangea paniculata ‘Vanilla Fraise’, which you can buy from Gardening Express, is a popular variety. It produces gorgeous, pyramid-shaped clusters of white-to-pink flowers. For potted plants that can be moved around the garden, Guy recommended Hydrangea serrata ‘Bluebird’ (available at Thompson & Morgan) for silvery blue flowerheads.
If you’ve already planted your hydrangea and it’s struggling, Guy says a few August hydrangea care tasks can help get them back on track.
‘Keep watering, give them liquid fertiliser every fortnight if the potted ones aren’t looking good, and if they’re getting scorched, move the pot somewhere shadier,’ he said.
Most importantly, Guy told us that it’s not the end of hydrangeas in the south.
‘Remember that we’re on the way down from summer now, so the nights are going to get longer and dewier, and the conditions are going to naturally get better for hydrangeas,’ Guy told us. ‘So, it’s well worth persisting and keeping them going.’
Panicled hydrangeas perform well in southern gardens.
This fertiliser is specially formulated to strength hydrangeas,
A layer of mulch will help retain soil moisture in hot weather.
The RHS’ news isn’t a sentence for hydrangeas in the south, but it does mean it’s wise to become more mindful about the way we grow the shrubs and the varieties that perform best in tough summers.
