北美的無霜日

2013-04-18 13:21:58

每年此時，都有人問：我什麼時候可以種花？

安全的種花時間是無霜日Frost-free Days。不論是農人，或是一般的園藝愛好者，都會知道什麼是無霜日。每年的無霜日就是農人種植的日子。如果你種的是怕霜的植物，就是所謂的一年生植物annuals，就非得等到無霜日之後才能種。而到秋天開始落霜之後，這些植物就會凍死。

多數的蔬菜類植物，好像蕃茄，瓜類，豆類，辣椒類植物都非常怕霜，一定要等到完全無霜害危險之後才能種。而一般一年生花卉類，也必須要等這一天之後才能種到土裡。這類包括常見的鳳仙花Impatiens，喇叭花Petunia，天竺葵Geranium，秋海棠Begonia，美人蕉Canna等。

過去無霜日都是在北美「農民曆」(Farmer’s Almanac) 中刊載，但目前可以在網上查到。知道無霜日的起始，可以計算那一年你住地區的種植時間有多少天。好像多倫多今年的無霜日，是由五月九日開始，到十月六日止，其間共有149天。也就是說，你可以在五月九日之後將怕寒的植物幼苗種在戶外地裡。而在未來的149天，植物才有機會成長。到了十月中，夜裡可能會落霜，凡是未收成的農作物就可能凍死。(不過這日期只是預計，到時還是要注意氣象報告，以免植物種下後遇到夜晚落霜，徒勞無功。一般都是遲幾天種，以防萬一。而怕寒植物如蕃茄，瓜豆類等，最好多等一兩個星期。)

另外你也可以查出每一種蔬菜類需要的種植時間，計算在你那一區，是否有足夠時間種那種作物。好像南瓜由幼苗種植開始，需要85-125天成熟；西瓜需要90天。而蕃茄則需要60-85天，更冷的地方可能就不夠時間。所以一般都是提早在室內播種，等天暖後移植幼株到戶外，或是在園藝店購買幼株回來移植，就可以確保有足夠時間生長。

 

下面是加拿大及美國各大城市無霜日圖表：

加拿大：

城市                全年無霜日天數                    起始                結束

Yellowknife       110天                                      May 27             Sept. 15

Victoria             200天                                      April 19             Nov. 5

Vancouver         221天                                      March 28           Nov. 5

Kamloops         156天                                      May 1               Oct. 5

Calgary             114天                                      May 23             Sept. 15

Edmonton         138天                                      May 7               Sept. 23

Winnipeg           119天                                      May 25             Sept. 22

Regina              111天                                      May 21             Sept. 10

Saskatoon         116天                                      May 21             Sept. 15

Hamilton           168天                                      April 29             Oct. 15

Ottawa              151天                                      May 6               Oct. 5

Toronto            149天                                      May 9               Oct. 6

Windsor            179天                                      April 25             Oct. 22

Kingston           160天                                      May 2               Oct. 10

Montreal           156天                                      May 3               Oct. 7

Quebec             139天                                      May 13             Sept. 29

Moncton            125天                                      May 24             Sept. 27

St. John’s         131天                                      June 2              Oct. 12

Halifax              166天                                      May 6               Oct. 20

Charlottetown    150天                                      May 17             Oct. 14

St. John           139天                                      May 18             Oct. 4

 

美國：

 

城市                                        起始                            結束

 

Birmingham， AL                     March 19                     November 14

Mobile， AL                             February 17                 December 12

Juneau， AK                             May 8                          October 4

Little Rock， AR                      March 17                     November 13

Phoenix， AZ                            February 5                   December 6

Tucson， AZ                             March 19                     November 19

Los Angeles， CA                    January 3                     December 28

Palm Springs， CA                   January 18                   December 18

Sacramento， CA                      February 6                   December 10

San Francisco， CA                  January 7                     December 29

San Jose， CA                           February 10                 January 6

Denver， CO                             April 16                       October 14

New Haven， CT                      April 15                       October 27

Hartford， CT                           April 22                       October 19

Wilmington， DE                      April 18                       October 26

DC， Washington                     March 29                     November 9

Miami， FL                               Never (全年均無霜日)

Tampa， FL                               January 10                   December 26

Jacksonville， FL                      February 16                 December 16

Atlanta， GA                            March 21                     November 18

Savannah， GA                         March 24                     November 29

Des Moines， IO                       April 24                       October 16

Sioux City， IO                                    April 27                       October 13

Chicago， IL                             April 25                       October 22

Springfield， IL                                    April 20                       October 23

Indianapolis， IN                      April 17                       October 27

Lexington， KY                        April 13                       October 28

Louisville， KY                                    April 1                         November 7

Wichita， KS                            April 5                         November 1

Topeka， KS                             April 9                         October 26

New Orleans， LA                    February 20                 December 9

Shreveport， LA                       March 8                       November 15

Boston， MA                            April 5                         November 8

Worcester， MA                       May 7                          October 2

Portland， ME                          April 29                       October 15

Baltimore， MD                        March 28                     November 19

Detroit， MI                              April 21                       October 20

Grand Rapid， MI                    April 23                       October 30

Duluth， MN                            May 21                        September 23

Minneapolis， MN                    April 20                       October 13

Kansas City， MO                    April 6                         October 30

St. Louis， MO                         April 9                         November 1

Springfield， MO                      April 12                       October 30

Hattiesburg， MS                      March 12                     November 19

Jackson， MS                            March 23                     November 9

Great Falls， MT                       May 9                          September 25

Helena， MT                             May 19                        September 18

Omaha， NE                             April 14                       October 20

Las Vegas， NV                       March 16                     November 10

Reno， NV                                May 8                          October 10

Albuquerque， NM                   April 13                       October 28

Santa Fe， NM                          April 24                       October 19

Concord， NH                          May 11                        September 30

Atlantic City， NJ                     March 31                     September 11

Newark， NJ                             April 3                         November 8

Albany， NY                            April 27                       October 13

Buffalo， NY                            May 20                        September 23

New York， NY                       April 13                       October 28

Syracuse， NY                          May 14                        October 3

Bismarck， ND                         May 11                        September 24

Wilmington， NC                     March 8                       October 24

Cincinnati， OH                        April 13                       October 23

Cleveland， OH                                    April 30                       October 23

Columbus， OH                        April 24                       October 20

Oklahoma City， OK                March 28                     November 7

Tulsa， OK                                March 25                     November 1

Eugene， OR                            April 13                       November 4

Portland， OR                           March 6                       November 24

Philadelphia， PA                     April 15                       October 15

Pittsburgh， PA                                    April 20                       October 23

Williamsport， PA                    May 3                          October 13

Providence， RI                                    April 13                       October 27

Charleston， SC                        February 19                 December 10

Rapid City， SD                       May 7                          October 4

Sioux Falls， SD                       XXX                           October 3

Memphis， TN                          March 20                     November 12

Nashville， TN                          March 28                     November 7

Dallas， TX                               March 18                     November 17

El Paso， TX                             March 26                     November 14

Houston， TX                           March 14                     November 21

Salt Lake City， UT                  April 13                       October 22

Burlington， VT                        May 8                          October 3

Richmond， VA                       March 29                     November 2

Seattle， WA                            March 14                     November 24

Charleston， WV                      April 18                       October 28

Milwaukee， WI                       April 20                       October 25

Cheyenne， WY                       May 14                        October 2 

 

相關文章：

北美植物耐寒分區表Plant Zone Map。

 

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