Is there a general rule to calculate the difference in ripening dates based on zone changes.
I know that there are many factors that effect ripening even within a given zone (sun exposure, altitude,rainfall, temp variation etc.), but is there a general “hubble constant” fudge factor that we can apply zone to zone ?
Mike
My guess is that the answer is “no”. The reason being that for example we have Zone 8 in Southern Georgia but there is Zone 8 in Washington State as well. Zone’s are determined by seasonal low temperatures. But winter in Zone 8 Washington will be a lot longer than winter in Zone 8 Georgia. Summers will be a lot cooler in Zone 8 Washington than in Zone 8 Georgia as well. Zone 8s are not even close to being created equal.
God bless.
Marcus
Marcus,
I hadn’t thought of zones in that way. And as I was reading your response my error crystalized in my mind.
Of course having three weeks of 32 degree temps as a low is different than 3 months
Thanx
Mike
Exactly. Also humidity, rainfall and summer heat are very variable as well in different regions of Zone 8. This is why “hardiness zone” for a plant only gives you a sliver of information. A person needs to keep asking questions about a given species or variety before spending money on a plant that may not be adaptable to your climate. My two favorite fruits to grow are pears and muscadines. Some pears do really well here in S. Georgia. But many that are listed as Zone 8 require way too many chilling hours to work here in Statesboro Georgia. LOL, Washington has humid weather, but Georgia adds lots and lots of sticky heat to the mix which for pears means lots and lots of fire blight pressure. Washingtonians can grow lots more pear varieties than we can here in Georgia. On the other side of it, Georgia is in the geographical and climatological center of the native range for muscadines. All muscadines love it here. I doubt summers are hot enough or long enough to ever ripen a single muscadine in Zone 8 Washington State.
One way to address this is to reference to a common variety. For apples, ripening times are sometimes reported relative to Delicious as in this table - Co-op Summary Table . If you know when Delicious ripens in your location, you can estimate when these other varieties will ripen. The USDA GRIN collection has similar but less detailed data apples vs Delicious.
Some nurseries have useful charts for multiple fruits that can be used in the same way. If you know when something on the chart ripens for your location, you can estimate another variety on the chart.
I think it’s interesting we start ripening varieties earlier in the season, but folks in the NE sort of catch up. I think Scott Smith actually passes me here, with some of his mid season/late varieties, even though we start sooner.