Quercus Closeup

In typical spring fashion, our April weather has run the gamut. Luckily, we’ve had more than of our share of “just right” conditions for gardening, with cool temperatures warmed by sunshine. A few days ago, however, our first major thunderstorm swept through with a squall line of strong winds and heavy rain.

Thankfully, we didn’t experience any damage and in the course of picking up the small branches that always litter the garden after high winds, I found something amazing.


Comparison of mid-April foliage of white and red oaks.

It was the branch tip of a white oak heavy with catkins (the male flowers that produce the wind-borne pollen that fertilize the female flowers) and best of all–tiny, perfectly formed baby leaves.

There are more than 600 species of oak worldwide (60 in North America) and the genus, Quercus, comprises two groups, white oaks and red oaks. White oaks, which typically have rounded lobes on their leaves, produce acorns that mature in a single year, while red oaks have pointed lobes and acorns that mature in two years.

Additionally, the groups can usually, but not always, be distinguished by their bark. In general, white oaks have bark that is a light to medium shade of gray, sometimes exhibiting a scaly appearance, while the bark of red oaks is typically darker in color and lined with deep furrows.


Comparison of the treetops, with the white oak on the far left.

Here, in my garden, the red oaks break dormancy a week or two before the white, and if you look at the treetops now, you can clearly see the difference. There is an even greater contrast in autumn, as the white oaks cling to their leaves into early December, well after all other deciduous trees are bare.

14 thoughts on “Quercus Closeup

    1. Marian St.Clair Post author

      Auto–Then you should begin with oaks, as they are superstars in the native plant world. In addition to the wildlife supported by their acorns, there are hundreds of associated insect species (and thus birds), as well as hundreds of associated lichens (medicines).

  1. Cathy

    Beautiful trees Marian. We are watching the oaks carefully here – no signs of growth yet. We have a saying: oak before ash, we shall have a splash, ash before oak, we shall have a soak! Not sure at all if it has any truth in it though! 🙂

    1. Marian St.Clair Post author

      I’ve never heard the rhyme before, but found an explanation on the internet that indicates oaks are more influenced by temperature and ash by day length, so if it is a warm spring (which theoretically leads to a drier summer) then the oaks leaf out first and if it is a cold spring then ash is first…but scientists say the rhyme has no foundation in truth. Here is the piece: http://www.bbc.co.uk/blogs/natureuk/2011/05/oak-before-ash-in-for-a-splash.shtml

      1. Cathy

        Thanks for the link Marian! The oaks are just leafing out now. But the ash buds are still fattening up!… We will see! 😉

  2. Lyn

    Great article Marian! Thank you. I will now have a more educated view of the many Oaks in my yard. And more knowledge about those darn acorns!

    1. Marian St.Clair Post author

      Lyn–There’s more to the acorn story. In a nutshell (LOL), the large acorns of the white oaks are low on nutrition but are very sweet and tasty so are eaten first, while the smaller acorns from red oaks are more nutritious but bitter with a high concentration of tannin, which is also a preservative. Near the end of winter, red oak acorns have not only persisted, but have become palatable from the washing effect of winter snow and rain, and they provide the needed food for wildlife to survive until the cycle of the growing season begins again.

  3. Kathleen

    Thanks for this. Knowing more about our graceful “neighbors “ warms my heart! Kathie onCapers St

    Sent from my iPhone


  4. Pauline

    No sign of leaves on our British oaks so far, they are always the last to come into leaf and the last to lose them, they sometimes stay until almost christmas!

    1. Marian St.Clair Post author

      Pauline–Yes, that is my one complaint about the white oak, which is such a beautiful tree. Often, I’m still struggling with leaves when it’s time to put up Christmas decorations!


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