Risky Plantings?

I am wondering how many chances do you take with your selection of types of fruits to plant? By this I mean zone pushing, or planting varieties of fruit trees, etc. that are purportedly incompatible with your region due to such things as heat, humidity, etc.?

In my case this year I planted an 850 chill hour plum even though my location averages 600 chill hours. I also have planted sugarcane even though it froze back to its roots the last few winters and I have completely lost about 1/2 of the ones I have planted likely due to growing conditions, and extremely hard winters.

What chilling hours Model you’re using? It seems that your zone and chilling hours aren’t correlated.

Well I zone push but some things are just too hard. I use containers for ones that won’t work any other way. I move inside or store in the garage. Some things like figs are very worth zone pushing but not so much some other fruits.

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In am on the 8b/9a line in Louisiana, however our chill hours are highly variable ranging from 400 hours to 1,200 hours

As a beginning gardener I killed 9 out of 10 plants. As an expert, I kill about 1 out of 100. In my opinion, trial and error plus study of pier-reviewed articles pertinent to your situation are equally important.


I may push zone up, if I have a way to protect the tree, but down seems very risky, you can’t chill when you need to.

If you have the room plant the stuff … then let nature decide if its any good. I was told various things would not work in my zone (fuzzy kiwis, muscadines, etc) and I planted them anyway and they worked fine. On the other hand pomegranates and figs have not worked out, the poms in particular I’m going to give about five more years before ripping them out.

For a plum you can always topwork it in a few years if its not fruiting reliably. The chill hours calculations have so many approximations in them that I would say its worth a go if there is no similar alternative plum.

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The plum was a cheap random Damson Plum, that I planted to have a second European plum for cross pollination, as I had received a free “Moldavian Plum” which is noted online as needing a pollinator from Raintree Nursery as a bonus item a couple of years ago. The Moldavian seem to be thriving here even though we had average and below average chill the last couple of winters, and Damsons appeared to have some of the lower chill hour ranges for European plums. So one bit of (free) risk taking on planting lead to a second risky planting for cross pollination.

As a rare fruit enthusiast, I am growing what isn’t supposed to be growing! Otherwise, if you grow the things that are abundantly growing in your area, it is way cheaper to buy them from the stores than grow them… but that’s just me. I know that the pride of growing it yourself is priceless.

So I push the border quite a bit.

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Sure you can chill when you need to…shade cloth will do that. Easiest thing unless you just love experimenting is to go with the printed zones and not push it in either direction.
(I like experimenting sometimes…but with a plant or two, not a whole orchard or huge plantings.)

I didn’t realized this will count as chill hours. I thought chill hours are ones bellow freezing. Though I never cared about them - we have real winter here. I use shade for my apricot now to delay blooming.

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Most nursery sells their fruit trees with chilling hours based only on the number of hours below 45F. There are other more accurate models that we have used in Crop Phenology simulations but the nursery folks don’t know the values for their fruit trees based on those models.

In UC Davis, during my graduate studies, we usually use the inputs from agrometeorological stations to calculate the various chilling hours used on the different models.


The reason why other models came up because there were some winter years when we had a series of pineapple express rains (warm rains brought by Jet Streams that passes over Hawaii) and we had chilling hours in the very low end and yet we had blooms on almonds and peaches. There are also other times when we had sufficient chilling hours because of the series of arctic blasts, but then little blooms on the fruit trees. So several chilling hour accumulation models were proposed and tested.


I’ve found that nurseries aren’t always honest about what zone a plant will work for. And that might not be intentional, it might just be a nursery is copying marketing material from another nursery or that true hardiness tests haven’t been done. So I think it’s worth it, if you have the space and patience. And like others mentioned, you can always protect a plant or otherwise help it survive if it’s one you really want.


You’re employed at UC Davis nowadays? Congratulations!

… given sufficient income and space.

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True, I think the best way to be risky about planting is to shop at a local big box store garden center. I was at one last week and I would guess 3/4 of what they had for sale was way too high of chill hour for my region, either that or not heat tolerant, etc.

Nope… when I was a graduate student at UC Davis… Crop Phenology that builds the Expert Systems for Agriculture was one of the projects I was involved with. then Intel hired me… paid more for computing… but I resigned later and worked on my own…


Oh. My daughter is a junior there now. How recently were you there in graduate school?


that’s great! It means you will visit! And if you visit, drop by and try some fruit wines from our house! Was involved with UC Davis 1990-1996. All my professors have already retired or have passed away.


Well yes … she transferred there last Fall and so nowadays I’m going about 4 times a year. Prior to that I’ve been visiting Wolfskill and the folks at the ANR extension on campus at least twice per year since 2003. :slight_smile:

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Yes, if you live in Florida and have 300 chill hours and plant a tree that requires 800 to break bud and bloom…that is a bad combination.

If you live in an area with 1500 chill hours and plant a blueberry or peach with 300 chill hour requirements, it will function just fine in the north…except for one thing, most years it will probably bloom out during a warm spell in the winter, then get frostbitten or frozen when a late cold snap comes along. Won’t kill the tree, but crops may be rare.

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