Longer days, warmer weather and flowers in bloom mean more time is spent enjoying our gardens.  Spring really has sprung and it’s early this year!  Our Southern red maples started flowering with gusto in early March followed by pear trees and cherry trees.   By the middle of March my Carolina jasmine, a few azaleas, Josee lilac and tulip tree ‘Jane’ were blooming.  Along the ground hellebores were still blooming with daffodils, periwinkle, Virginia bluebells, bloodroots, trilliums, and even my bridal wreath looked like a big cotton ball.  But with all that beauty came early spring winds with clouds of pollen from pine trees, depositing large amounts of yellow dust on everything, making its pollen and early blooming flowers unpleasant for me…achoo!

With this early progression of the spring blooms, comes the early release of pollen.  If flowers are open and mature, they are releasing pollen.  More frost-free days and longer growing seasons is a positive for gardeners, but these changes can make allergy season arrive earlier and stay longer.  In fact, a 2020 study from the National Environmental Education Foundation (NEEF), found that in North America there is now 21% more pollen in the air an average of 20 days earlier each year compared to 1990.  And, as much as I am not a true follower of many organizations because statistics can be tweaked to fit their funding circumstances, I do believe that climate change is occurring and has been since the beginning of time.   That means that some years we have more pollen and allergies are worse...this is a bad year!

That doesn’t mean I don’t enjoy the kaleidoscope of spring colors in our gardens.   But here is the question, how does a tree know that winter is likely over?  It’s rather simple!  The length of winter chilling, day length, and spring warmth play roles in bud break.  Most trees need a period of chilling called dormancy.  Dormancy is when a tree conserves its energy into its roots to survive the frigid season.  This is followed by 3 important factors: sunlight, warmth and moisture signaling plants to break their buds.  With our record-breaking cold January, and then warmer than usual February and March, the buds started emerging earlier. 

Trees can sense spring is arriving as the days get longer, meaning more sunlight each day.  Daylight isn’t going to change from year to year.   After December 21 the days start to get longer which means more sunlight.  Then comes the spring solstice or vernal equinox, the first day of spring where the sun rays are directly over the equator resulting in approximately equal hours of daylight and darkness worldwide.  After that, the days get longer in the Northern Hemisphere, giving us more sunlight and signaling plants that it is time to start breaking their buds.  But trees also need moisture and warmth, which can vary from year to year, and could speed up or slow down when buds decide to open.

We often associate the seasons with the stages of the trees.  We notice when trees flower, leaf budding, fruit setting, and leaf dropping throughout the year.  The study of the time and duration of these stages is known as phenology.  This attention to plant phenology is also observed by our insects, birds and small mammals with their own life stages associated with plant stages. And this is important for the pollination of our trees.

In the late winter, trees pay attention to temperature and the length of daylight hours. These 2 factors mainly signal trees to start moving resources, stored overwinter in their root systems, up to the canopy.  Water, nutrients, and sugars travel through cells in the tree trunk to the buds on branches. The buds then swell and open to flowers and leaves.  If a hard freeze occurs, flowers and leaves can have some damage.

Some deciduous trees will first break bud and develop leaves, others will start the season with flower development.  Early flowering trees are especially important in the landscape as they offer the first chance for pollinators to harvest food and begin to grow their population.  

The red maples mark the start of spring for me but there are many other native trees that begin flowering in March: Eastern Redbud, Carolina Silverbells, and dogwood trees, and so many more.  Note that the Bradford pear tree is not one of our natives.  But instead, it is invasive and can be damaging to our ecosystem!

Spring is here and it is a season of beauty and renewal.  In the South, vibrant flowers bloom from early to mid-spring.  Some of the most beautiful displays come from trees.  They bring life and color to our gardens and yes, pollen, too.  Now is the time to get out into our gardens to enjoy the flowers and pollinators once again...a-achoo!●