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Conifers and our US weather variability

Reading another note about the weather and planting times I wanted to show some differences in climate in the US.

Here are the projected highs(and historical averages) over the next 5 days for 5 major cities in different regions:

CHICAGO, IL, Historical averages(80):

65, 74, 75, 76, 76


86, 80, 78, 81, 84

ATLANTA, GE, Avg. 86

92, 92, 89, 92, 91

HOUSTON, TX, Avg. 92

93, 95, 95, 93, 95

SEATTLE, WA, avg. 69

68, 63, 66, 64, 65

The proximity to the ocean, but more importantly, that the winds usually blow west to east bringing in the cooler ocean air(and clouds) keeps our temps on the West Coast very cool in comparison to much of the country.

To me, this is most evident in Spring but also obviously has effects on planting times and heat issues with some plants as well.

Spring in most of the country is a brisk season, often transforming cool and sometimes snowy landscapes into a booming, explosion of growth and plants waking up/pushing leaves. Daily highs explode some twenty degrees on average in about three months. Meanwhile, Spring in the Pacific Northwest is an oxymoron. The weather lumbers from our cool, mild winters into a less-cool, mild, wet Spring. We rarely see fully sunny days more then once a week and temps almost never reach 70 until early June or later.

Plants wake up in various rates, and wake up slowly. I am always amazed to see photo galleries from Dave(dcsteg) and others showing robust growth weeks after I hear about near blizzard like conditions in Kansas. Here, plants push so slowly that many aren't waking up at the same time. I can have a cherry tree flower completely, drop all of the flower petals and then start leafing before other trees even open their buds. Conifers also are wildly irregular. Last Winter, Picea glauca cultivars pushed TWICE before my pines began making their Spring candles. This was literally five months apart, the Pines waking up in June while Picea glauca's were starting to push in February.

Colors are different as well. Plants that have a 'Spring flush', can show these colors for much longer periods of time in cooler climates. Some DON'T change much at all. A classic example Picea orientalis 'Daureas' in my garden and also 'Keith', his pushed bright gold and turned dark green in 2-3 weeks, my specimen was gold by June and stayed a gold-green hue all year.

Again, a few examples of Spring transition temps:

Wichita, KC

Avg. March high temp: 56

High/Low Temp, this March 84, low of 24!

Avg. April temp: 67

High Temp, this April: 90

Avg. May temp: 76

High Temp, this May: 100

Seattle, WA

Avg. March high temp: 53

High/Low temp, this March: 62, low of 34

Avg. April Temp: 58

High Temp, this April: 66(ONLY DAY ABOVE 60 IN APRIL!)

Avg. May Temp: 64

High Temp, this May: 70.

So a few quick eye-opening stats here. Wichita was warmer on average then any single day in Seattle this April.

Wichita had a warmer day March 17(80) then Seattle has seen since last September!

One mor extremely, curious stat. In February, Wichita had a daily high of 11(ELEVEN!) on February 1st and then 16 days later a high of 78. Seattle hasn't seen a temp that cold in 2-3 years(and probably only a few dozen times in it's history), and has only hit 78 recently, in a early June 'heat wave'.

I remain staggered by the differences in our country, even in locations about a thousand miles apart.


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