Massive rare plants that can take decades to flower have "burst into bloom for the first time" at a garden in the United Kingdom, said SWNS, the British news service.

And it's all thanks to the heat wave.

The furcraea longaeva grow to over 16 feet tall.

BRITISH WOMAN GOES VIRAL FOR BRINGING DYING PLANTS ‘BACK TO LIFE’ WITH HYSTERICAL $5 HACK: ‘GENIUS’ 

And they can take over 25 years to show flowers, SWNS noted.

But for three plants, last year's warm summer combined with a cold winter and now a hot spell have led to their blooming at the National Trust's Overbeck's Garden, near Salcombe, Devon, in southwest England, said SWNS.

The news that they're flowering, however, isn't necessarily the best, according to those in the know.

It means the plants may be dead within the next two weeks, SWNS said.

Gardener Sam Elliott planted them at Overbeck's Garden a decade ago, he said.

He told the BBC, "They can take 10 years to flower, but possibly up to 25 years, in some cases."

He also said, "It will leave tiny 'bulbils' that we will use to propagate future plants. It is very exciting to see them flower for the first time."

He also told the BBC, "It's monocarpic, meaning it will flower once — then die as it spends 10 years building up energy in leaves, stem and roots."

The plants are described a "huge, spiky (but soft) exotics from Mexico," according to Architectural Plants. 

"After many years, they send out 30 foot yellow flower spikes."

Because of their size, they are "extremely noticeable," the site also said.

"They form a big fat trunk (to 6 feet after many years) and leaves, which are 4 or 5 feet long," the same source noted. 

"Sometimes the trunk becomes so tall, they keel over under their own weight and appear to snake along the ground."

Also, "there seems to be some confusion over the nature and size of the trunk," said Architectural Plants. 

CLICK HERE TO GET THE FOX NEWS APP

"Pictures of the plant growing in the wild will show a petticoat of old leaves hanging down and obscuring the trunk. In cultivation, gardeners tend to remove these old leaves, displaying the trunk — sometimes 1 foot in diameter."

CLICK HERE TO SIGN UP FOR OUR LIFESTYLE NEWSLETTER

It added, "The relationship between the height of the trunk at the time the plant flowers is non-existent; it could flower at any time."