Forest Preserve District of Cook County, Illinois
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A Remarkable Spring
Nature Bulletin No. 423-A   June 12, 1971
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

This is the last nature bulletin until September 11 when No. 424-A will be issued. The schools are closing and summer is here. In fact, according to the calendar, it has been here since early May.

Every year since 1945, we have kept close track of the first signs of spring and its progress -- when the various kinds of wildflowers bloom, when the trees and shrubs bloom and deck themselves with leaves, when the birds arrive and the frogs sing -- phonology records, they are called. But, this year, spring was drawn out and things happened slowly at first and then so fast, that we could hardly keep up with them.

Nothing remarkable occurred during February and most of March. We have earlier records of when plants bloomed and birds arrived in 1945 and 1946. But after a cold snap in March and April, Mother Nature slowly started to respond. We had a cold April, with freezing temperatures on several dates. Early May was also cool, with several nights of frost. Three record lows were recorded on May 2, 3 and 13th. As a result, many plants developed and bloomed so much later than usual.

It used to be time to plant corn when the new leaves on the white oaks were as big as a squirrel's ear -- usually about May 10. This year, here in Cook County, they finally reached that large by the 15th of May. The red oaks, always earlier, were leafing out and blooming during the first week of May. The earlier elms, maples, cottonwoods and most of the other shade trees were also late.

Lilacs bloomed here on May 9th, behind their usual date but, because of cool weather, the clusters were long-lived. On 'Decoration Day", there were always bushels of peonies to decorate the graves of our grandfathers and uncles who fought in the Civil War but around Chicago, ordinarily, only the commercial growers have peonies available on May 30th. This year they were blooming in many suburban yards during the week of May 24th. Cultivated varieties of shrubs, such as Spirea or "Bridal Wreath", bloomed ten days later than the average date.

The hawthorns, except for the late-blooming species, and the wild crabapples, which usually glorify our landscapes with masses of white and pink-tinged blooms about the middle of May, were at their peak on time, May 15th and 16th. The fruit trees -- apples, plums, pears and cherries -- were in full bloom about two weeks earlier.

Chicago weather is so variable and influenced by so many factors including the Illinois River valley and a huge body of water, Lake Michigan, that it is almost unpredictable. Somebody said: "If you don't like our weather today, just wait a while". It has many extremes and abrupt changes, as demonstrated in these first five months of 1971. The result is a climate that keeps us guessing, "on our toes" and virile; with a motto: "I will". It is salubrious.

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