{"id":5213,"date":"2019-04-05T16:27:23","date_gmt":"2019-04-05T23:27:23","guid":{"rendered":"http:\/\/gregalder.com\/yardposts\/?p=5213"},"modified":"2023-02-24T13:52:28","modified_gmt":"2023-02-24T21:52:28","slug":"messages-from-your-deciduous-fruit-trees-after-the-chilly-winter","status":"publish","type":"post","link":"https:\/\/gregalder.com\/yardposts\/messages-from-your-deciduous-fruit-trees-after-the-chilly-winter\/","title":{"rendered":"Messages from your deciduous fruit trees after the chilly winter"},"content":{"rendered":"\n

Deciduous fruit trees demand to spend their winters in certain ways. Peaches, plums, apricots, apples, cherries, nectarines, they like to get chilly in the fall, then shed their leaves and stay chilly for a certain length of time, then warm up in the late winter or early spring and make flowers — a bunch of flowers all at once.<\/p>\n\n\n\n

Pictured above are some of my stone fruit trees making a bunch of flowers all at once. They are telling us that they had a fantasticly chilly winter. They are suited to the past winter\u2019s weather in my yard.<\/p>\n\n\n\n

On the other hand, the same trees were sending a very different message at this time last year, after an unusually warm and wacky winter. (See my post about last winter, \u201cEffects of a warm and wacky winter on deciduous fruit trees.\u201d<\/a>) Here is my Flavor King pluot \u201cin bloom\u201d last year:<\/p>\n\n\n\n

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And here it is this year:<\/p>\n\n\n\n

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How do your deciduous fruit trees look this spring? Are they flowering in a heavy, concentrated way? If not, then don\u2019t expect them to do so consistently in the future.<\/p>\n\n\n\n

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What kind of winter did we have?<\/strong><\/p>\n\n\n\n

Many parts of Southern California had a winter for the record books, just like my nook of San Diego County did. I\u2019m in an area called Ramona, and the National Weather Service says<\/a> that in February we had the coldest average temperature ever recorded: 47 degrees.<\/p>\n\n\n\n

More important for deciduous fruit trees, January and December were also consistently cool. The winter of 2018-2019 was three successive months of steady chill. I keep temperature records for my yard, and the highest temperature between December 1 and March 15 was only 71 degrees. And in February there were two full weeks where my yard did not even rise as high as 60 degrees. That\u2019s cool, consistently cool.<\/p>\n\n\n\n

We never even had our usual Santa Ana spell around New Year\u2019s. It was the best winter for deciduous fruit trees that we can hope for.<\/p>\n\n\n\n

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Dapple Dandy pluot flowers singing, “Thank you for that winter!”<\/figcaption><\/figure>\n\n\n\n
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What do deciduous fruit trees want from a winter?<\/strong><\/p>\n\n\n\n

Deciduous fruit trees of all types vary slightly in their winter preferences in terms of how long the winter lasts and how cold it gets, but they all seem to have an internal clock that counts how long it stays cool and whenever they\u2019ve reached their requirement, they wake up and flower. A Babcock peach only needs to be chilly for a short time while a Bing cherry needs to be chilly for longer.<\/p>\n\n\n\n

(For more about winter chill needs of deciduous fruit trees, see my post \u201cEffects of a warm and wacky winter on deciduous fruit trees.\u201d<\/a>) <\/p>\n\n\n\n

Researchers are continually learning more about exactly what deciduous fruit trees need in their winters, and last week I listened to an interesting interview with one such researcher named Katherine Jarvis-Shean<\/a> of the University of California. About the fact that trees prefer consistent chill, Jarvis-Shean likened winter to filling a bucket. Cold nights fill the bucket, but a winter warm spell (Santa Anas near New Year\u2019s, e.g.) dumps out some of the accumulated chill.<\/p>\n\n\n\n

Jarvis-Shean also noted that during unusually warm winters pollenizers sometimes don\u2019t bloom at the same time as the trees they\u2019re meant to pollenize. Pluots, for example, need to be pollenized by another pluot or certain plums. Unusually warm winters will cause these trees to bloom at different times compared to when they meet their chill requirements in a colder winter. <\/p>\n\n\n\n

I saw this at work with my pluots and plums last year compared to previous years — and compared to this year. I even shot a short video of some of them in bloom here:<\/p>\n\n\n\n