Cold weather delaying wisteria bloom

Wisteria is set for a ‘wonderful year’ because of the relatively wet summer last year, followed by a mild autumn – James Linsell Clark / SWNS

The cold snap is delaying a bumper bloom of wisteria, the Royal Horticultural Society (RHS) has said, as forecasts suggest wet and windy weather is on the way.

Wisteria is set for a “wonderful year” because of the relatively wet summer last year, followed by a mild autumn, said Guy Barter, the chief horticulturist at the RHS.

But the recent cold snap, which has caused temperatures to drop as low as -3C in northern England and Scotland, is stopping them from blooming.

“They are in a state of stasis and as soon as it warms up, they will come,” said Mr Barter. “It’s also affected plants like the bearded irises, which were on the cusp of coming out a couple of weeks ago and are now staying steady.”

“Cold weather affects the rate of growth in flowering so while the temperature is falling below 10 then growth is much more slowed down, particularly the night temperatures which have been around 4 or 5C.”

“We were running about two weeks early before the cold snap so it’s kind of pushing us back to normal.”

Cold keeps flower in bloom for longer

Temperatures have reached highs of just 13C this week thanks to a northerly wind, below the average for this time of year, which should be closer to 14 or 15C.

Mr Barter said the colder temperatures also meant that some flowers already out would stay in bloom for longer.

“There’s a plus side which is that things that were already out like late daffodils, tulips and shrubs are all standing steady,” he said. “The cold actually slows down the deterioration of the flower so you can enjoy them for longer.”

But he warned that tender plants such as tomatoes, chillies, petunias and dahlias should be left in the greenhouse or the garden centre until temperatures increase.

The Met Office said temperatures would slowly rise from Sunday, but more rain was also on the way.

“It will stay fairly bright for northern areas through Saturday, and I think most areas should stay dry, particularly across north and west, but it will turn a bit cloudier throughout the day and it will still feel fairly cool,” Annie Shuttleworth, the Met Office’s meteorologist said.

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