All blooming at once Chris J. Ratcliffe / Getty

UK gardens are likely to be ablaze with colour this week as plants all break into flower simultaneously.

This “condensed spring” follows much dismal weather: the UK spring has seen snow, twice the usual amount of rainfall and temperatures that are below average.

“Cold has held spring back by two weeks, so suddenly everything will come out in a rush,” says Guy Barter at the Royal Horticultural Society, which has forecast the condensed spring.

Plants need a period of cold to kick-start genetic programs for flowering. “It’s like a sort …