People Are Just Realising Why Tree Blossoms Come Out Before Leaves, And It’s So Smart

We’ve recently shared what those slightly ominous black clumps in the branches of trees really are (and no, they’re not nests). 

Like Tom Hanks, we learned the real reason leaves lose their colour in autumn too ― it’s not just because they’re dying. 

And thanks to a Reddit post shared by u/YungstirJoey666, we’ve come to realise (along with other members of the site) why trees blossom before their leaves re-grow. 

In his entry, the Redditor was concerned about the presence of blossoms without accompanying leaves, writing: “I feel that the landscape and foliage look somewhat unbalanced when I see colourful buds combined with empty tree branches.” 

So why do they erupt before the greenery?

Some plants are ‘hysteranthous’

Commenter u/Friendly_Coconut wrote: “Blossoms [regularly] hit before leaves. Trees don’t really start to leaf out until April and blossoming trees tend to peak in mid to late March.” 

Their verdict is shared by Loyola University New Orleans, which said tree reproduction takes priority after the winter hibernation.

“Since reproduction is so important, the adaptive strategy of pre-leafing flowering is to use those energy stores to produce flowers that provide the seeds,” they shared (though not all trees follow that strategy). 

Additionally, the lack of leaves on some trees mean flower buds don’t get sunlight taken away by their green siblings before they have a chance to bloom. 

Brockwell Park Community Greenhouses explained that this pattern, of putting flowers out before leaves, is known as hysteranthous.

In the UK, most trees are expected to get their leaves back between March and April.

Wait… how do blossoms help a tree reproduce?

The flowers contain all-important pollen, which incidentally is the thing that might have set your hay fever off early this year.

Insects or the wind carry pollen from one flower to another (pollination). When the pollen hits the new flower, it reaches the second flower’s ovaries and creates a seed. 

Those seeds are then dispersed by the wind or animals and grow to become another plant or tree.