Checked today and we’re over 300 hrs already.
Was just reading something interesting about a new way to calculate chill called the Dynamic model, see below. Evidently it’s better for warm weather climates where the temps can swing during winter time. It allows for a gain and loss of chill portions. This year we’re at 17 chill portions for my area. Will be curious to see if sellers of different fruit trees will start using this as the new guideline for calculating chill.
In the Dynamic Model “chill portions” accumulate with cool temperatures and are lost with warmer temperatures from 33-550F. To make it even more complicated, some cool temperatures are more effective than others. The Dynamic Model, using “chill portions”, is a much more stable measurement – it varies less from year to year in any one place than “chill hours” do. The University of California produced a program you can use with hourly data from a datalogger to calculate chill portions. The University of Florida calculates chill portions for you at the Florida Automated Weather Network (FAWN) site. When you look at the current observations for any selected site, on the left side it offers the Chill Portions (Dynamic Model).
I think we got 300 chill hours in the last two weeks!
If anyone wonders what the consequence of too many chilling hours. My low chill Golden Boy Pear is beginning to break bud just a little. This is in the middle of a January where we have had freezing weather at least one day every week and got down to 25 last night and 22 two nights ago.
This late January heat wave has me a tad bit nervous
As I mentioned earlier, this has been one of the cooler winters in recent memory. Having said that, all of my trees appear to be gearing up already for spring…Hard to imagine that in another two weeks I’ll be applying my first application of citrus fertilizer for the year.
Buds on one of my pear trees…
Don’t know about blooms and fruit yet this year, but a couple weeks ago I cut some shoots and put them in a vase to see if the -9F weather (on two different occasions) did any damage.
I cut some off Johnboy, which is somewhat of a winter tender cultivar, Ernies Choice, and Lucky 13. Doesn’t look like any winter damage, based on these shoots. I see the fruit buds swelling. The one in the middle is in green calyx.
I used to prune in Feb to get shoots for forcing
Way too early to tell , check back mid April.
I’m seeing some bud swell on my stone fruit. It is sort typical for us but I don’t like to see it this early. Next week’s forecast is for 40’s and 50’s. Last year was a total loss. I don’t want a repeat of that.
Well, things are looking bad over here. Fruit buds are starting to swell and it is early February. Last year my first bloom (apricot) occurred on on March 20th. This year I think my first bloom will likely happen in late February. Forecast looks warm, especially on the sunny days…
Curious if any of y’all have painted the trunks of your trees white to delay bloom.
@jeremymillrood, @Phill_Boise_7a, @Graftman
The theory is that even in cold air temps the sun can warm the dark tree trunks and cause expansion and sap flow. My Anna apples had silver tips in January after a stretch of sun so I went out and painted all the trunks - which I had intended to do last fall but the winter was more intense than usual here with no breaks. Despite all the cold air temps, she thinks she had enough chill hours and wants to go spring in Jnauary. Hope that white trunk she is sporting now slows her down.
I used to paint the trunks and I think it helps. I should get back to doing that. My apricot is in the front yard and would odd with a painted trunk but the others could be painted. In fact I thought it gave them a finished look.
I painted my tree truncks few days ago when the weather was warm. The paint remains on the truncks so I only do it every other year. However, while I am painting the truncks, I found my seeding peach trees have gummy at base of the trees, a sign of peach tree bore! I removed some soil, used screw driver to remove brown bark . Guess what， I found couple of fatty white worms hiding right under the bark! This is first time I have to deal with peachbore. My other older peach/nect don’t get bore. Maybe it has to do with the grafted rootstock?
Phil, in my head I always thought of Idaho as pretty similar climate wise to Minnesota. I can’t get over those temps! I could be outside playing tennis there everyday in February! It does stink for keeping fruit trees asleep tho
I’d thought about painting, even bought the paint, just never got around to doing it. My understanding was the paint kept the trunks from getting sunscald or borers, not so sure about keeping it cool enough to prevent them from budding out. I think that’s more related to the tree following it’s biological/environmental clock, but I’m no expert…
The southwest of Idaho where Boise is located is quite a bit different from the rest of the state. We have had very nice weather this winter.
I haven’t painted any trunks, not because I don’t think it won’t work, but because I am not a big fan of how it looks. I like the look of natural bark, even if it is foolish.
I’m very concerned with the crazy weather but time will tell.
Clark, you’ve been a grower for a long time. Has a year gone by where you haven’t been concerned about the weather, or, someone said to you, “this weather is crazy!”?
The best we can do is to come up with a way to modulate the extremes that affect what we are growing. Row cover, polytunnels, shade cloth, placement, painting trunks, etc
In January we often have a spell of spring weather, sunny, even into the 70s and still have plenty of time for more actic dips to come through here. During a warm spell, my attention was drawn to the beautiful dark trunks of the plum trees, and I went over and felt them. They were warm from the sun. I thought, whoa, that can’t be good in January. I could have wrapped them with something reflective (I don’t have many trees) until it was a better time for sap to move and then uncoverd them. But painted them white instead. This will help modulate the weather extremes and hopefully delay early bloomers so I get fruit.