Showy flowers

Flowers, Pollen and Allergies

Is that tree causing your allergies?  That pretty tree with the white flowers?  That pine tree covering your car in green film?  Nope. It’s the trees you don’t see that are getting you.This is the height of allergy season. You can feel it in your sinuses and see it on your car windows. Huge amounts […]

sugar maple flowers

More tree sex – sugar maple

Have you seen the sugar maples in flower?  In Kentucky, they are flowering right now, but you need to look closely to see them. The flowers are not very show, their pale green blending with the green riot that is spring.  These interesting flowers will reward the careful observer.  Sex in maples is complicated. Even […]

Why do trees hold on to their leaves?

Why do trees hold on to their leaves in winter?  We get asked this question quite often.  The short answer for the impatient reader is sex, or more specifically, puberty.In some years, cold weather comes on so suddenly that leaves are killed by frost.  Last year, a sudden cold snap came on the heels of […]

Winter Sex: The Puzzling Case of Witchhazel

This is part of our ongoing series on tree sex.  Witchhazel is one of the most beautiful shrubs or small trees in forests throughout the temperate zone.  It is easy to overlook in the summer, mixed in with lots of other shrubs and trees along creek banks and moist lower slopes of forests.It is in […]

More Tree Sex at Under Main

The nice people at Under Main worked with me to put together a tree sex video and story.  See the whole thing at Under Main, or go straight to the YouTube video.  More to come!    

Male and female catkins of black alder

Tree Sex Part 3

Some trees are pollinated entirely by wind.  Many wind-pollinated hardwood trees make complex slender compound flower structures called catkins. Later this spring, we will see catkins in all our oak trees, mulberries, walnuts and chestnuts, and further north on true poplars. Now, in early spring, you will notice catkins on alders, willows and birches. Male […]

Tree Sex, Part 2

Many early spring trees are pollinated both by wind and insects.  For insects, these early spring trees can be critically important.  At a time when few plants are flowering, bees and other insects rely on trees for pollen.  Most early spring trees produce little or no nectar, and are much more important as a pollen […]

Flowering schedules in alpine flowers are changing

A 39-year record of wildflower blooming in the Rocky Mountains  shows that climate change has altered the timing of blooming for most species in an alpine meadow.  (Link is to University of Maryland press release. Original paper published in PNAS). The blooming season now runs from late April to late September instead of late May to […]

Tree Sex

It’s Spring and time for trees to start their amazing sexual displays.  Tree flowers are often small and subtle, but will reward your close attention.  This is a  silver maple flower with the female parts fully expressed – the stigma is a sticky surface ready to receive pollen from another tree.  The male parts in […]