Site Selection and Winter Sun Exposure

[finewines25]

Hi all,

I'm planning to plant some Cab and Chardonnay in a Northern California climate (a bit away from the coast, so summer days are hot and there is only limited fog).

I have a couple of site options on an E/SE facing light slope. However, due to the surrounding terrain, sun exposure is shortened to about 8-9 per day around this time of the year (April). From around Nov to Feb, there is little to no direct sunlight for these sites (even with surrounding vegetation cleared and trimmed). Will this be an issue for the plants and growing decent grapes for wine making, particularly in the wet winter months or could plants be healthy with no light during dormancy? I suspect there's at least high chance for fungus grow.

Thanks for your opinion and shared experiences!

 

[CortneyD]

How is the breeze at the site Nov-Feb? Stagnant air/high humidity is traditionally the biggest invitation for fungus, so I'd wager that with good air circulation and/or drier air, the lack of light wouldn't be a huge issue since the plants are dormant.

 

[finewines25]

Thanks! There are some lightly windy days throughout the year, but would say at least an equal amount of days with stagnant air. May have to monitor more closely... Some trees in the neighborhood grow some moss.

 

[ChuckD]

Just curious. Are we talking commercial scale? Hobby? Or somewhere in between?

 

[finewines25]

Hobby. 1/8-1/4 acre max.

 

[tmcfadden932]

What makes you want to grow cool weather grapes in a hot environment that is only going to get hotter as the years go by?
There are good grapes, both white and red, that will do well in the heat, Spanish and Italian varietals come to mind.
I take care of a 1/3 acre vineyard in Wilton, Ca. where it gets hot. In 2021 we had a heat spike that took temps a week before harvest over 100F and raisined up the fruit real good and I had to work with sugar at 29%.
Spanish Albarino for a white and Tempranillo for a red do well in the heat and Tempranillo makes a nice Rose' too,
Italian Barbera makes both a nice white and you can use the skins in your red. Both Aglianico and Montepulciano make wonderful reds and rose'.
The East/ Southeast slope is going to cause problems with any grape. Tempranillo is an early ripening varietal and would be your best bet. Cab Sauv takes 180 days from bud break to ripening. In Wilton, Ca., in full sun, ripens in early October. so I would not recommend that varietal.

 

[ChuckD]

Hobby. 1/8-1/4 acre max.

I’m starting a hobby vineyard myself this spring. Only cold hardy grapes for me.

 

[finewines25]

What makes you want to grow cool weather grapes in a hot environment that is only going to get hotter as the years go by?
There are good grapes, both white and red, that will do well in the heat, Spanish and Italian varietals come to mind.
I take care of a 1/3 acre vineyard in Wilton, Ca. where it gets hot. In 2021 we had a heat spike that took temps a week before harvest over 100F and raisined up the fruit real good and I had to work with sugar at 29%.
Spanish Albarino for a white and Tempranillo for a red do well in the heat and Tempranillo makes a nice Rose' too,
Italian Barbera makes both a nice white and you can use the skins in your red. Both Aglianico and Montepulciano make wonderful reds and rose'.
The East/ Southeast slope is going to cause problems with any grape. Tempranillo is an early ripening varietal and would be your best bet. Cab Sauv takes 180 days from bud break to ripening. In Wilton, Ca., in full sun, ripens in early October. so I would not recommend that varietal.

Thanks for all the tips. I'm in the East Bay area (near Pleasant Hill, CA with a heat summation of around 3,500 degrees per year). We get some hot summer days, but it's not as hot and dry as the Central Valley. I wanted to go with some Chard and Cab due to some personal preference, but will look into Tempranillo. I have some sliver of higher-up property that gets good sun exposure and could be used for 4-5 plants of some varietal that requires more sun exposure.

 

[finewines25]

I’m starting a hobby vineyard myself this spring. Only cold hardy grapes for me.

Sounds like you are further North-East? Spring should be on its way.

 

[ChuckD]

Sounds like you are further North-East? Spring should be on its way.

I’m in NE Wisconsin, and the calendar says so but three inches of snow last night and more coming. I suppose it’s better than last year when we had an early spring then a real late frost. I lost the blossoms on a few apple trees and heard some vineyards lost a lot of buds to frost.

 

[CortneyD]

What makes you want to grow cool weather grapes in a hot environment that is only going to get hotter as the years go by?
There are good grapes, both white and red, that will do well in the heat, Spanish and Italian varietals come to mind.
I take care of a 1/3 acre vineyard in Wilton, Ca. where it gets hot. In 2021 we had a heat spike that took temps a week before harvest over 100F and raisined up the fruit real good and I had to work with sugar at 29%.
Spanish Albarino for a white and Tempranillo for a red do well in the heat and Tempranillo makes a nice Rose' too,
Italian Barbera makes both a nice white and you can use the skins in your red. Both Aglianico and Montepulciano make wonderful reds and rose'.
The East/ Southeast slope is going to cause problems with any grape. Tempranillo is an early ripening varietal and would be your best bet. Cab Sauv takes 180 days from bud break to ripening. In Wilton, Ca., in full sun, ripens in early October. so I would not recommend that varietal.

My observations re: plants and heat tolerances as a Master Gardener. I still recommend folks planting things hardy to the cooler end of their zone because, while temps are rising, we are still getting major cold snaps (and unseasonable ones at that) across the nation and even in areas that historically have not had these events. Planting at the top end of your growing zone means those plants may not survive a poorly timed cold snap or cold-weather event (see much of Texas after the week's long winter weather). If you plant cool-adapted plants you can more easily mitigate hot weather events (shade cloth, extra watering, strategic pruning) than you can mitigate cold snaps. Or you shoot the gap and go for something thats puts your growing zone in the middle of its recommendation. But that's my plant-forward line of thinking that prioritizes plant health and survival- it isn't a fruit-production based recommendation. Just my 2 cents!

 

[tmcfadden932]

My observations re: plants and heat tolerances as a Master Gardener. I still recommend folks planting things hardy to the cooler end of their zone because, while temps are rising, we are still getting major cold snaps (and unseasonable ones at that) across the nation and even in areas that historically have not had these events. Planting at the top end of your growing zone means those plants may not survive a poorly timed cold snap or cold-weather event (see much of Texas after the week's long winter weather). If you plant cool-adapted plants you can more easily mitigate hot weather events (shade cloth, extra watering, strategic pruning) than you can mitigate cold snaps. Or you shoot the gap and go for something thats puts your growing zone in the middle of its recommendation. But that's my plant-forward line of thinking that prioritizes plant health and survival- it isn't a fruit-production based recommendation. Just my 2 cents!

East of the San Francisco Bay does not have a winter as you know it. Temps get down to around 32F and that's about it. Frost happens about once every 20 years, except on the mountains. I moved from Ohio to California 40 years ago and found what you learned as a grower there does not apply here. It's the heat that causes problems.

 

[Snafflebit]

Thanks for all the tips. I'm in the East Bay area (near Pleasant Hill, CA with a heat summation of around 3,500 degrees per year). We get some hot summer days, but it's not as hot and dry as the Central Valley. I wanted to go with some Chard and Cab due to some personal preference, but will look into Tempranillo.

May I suggest choosing grape varieties that can all be blended together, such as Cab and Merlot or Cab Franc

 

[CortneyD]

LOL @tmcfadden932 . Of course San Fran doesn't have Wisconsin or Midwest winters!!!! I'm just saying, as someone who has lived and gardened in Texas as well as Wisconsin, that cold will always be an issue. Hot temps won't kill the plants (but obviously can impact yields and quality) but just a few days at or below freezing can kill everything and the entire investment is lost, not just that year's harvest. Just look at the horticultural devastation in the South after last year's winter storm. It is always worth taking that into account when investing in long-term crops like trees and fruit plants.

 

[BigH]

However, due to the surrounding terrain, sun exposure is shortened to about 8-9 per day around this time of the year (April). From around Nov to Feb, there is little to no direct sunlight for these sites (even with surrounding vegetation cleared and trimmed).

I am really not qualified to answer your question. My climate is just too different. I recommend that you find a grape grower in your area and try to talk to them. What are they growing, and have they tried growing the varieties that you want to grow? Planting a the wrong variety for a given site is a 10 year headache that you want to avoid. You have to plant varieties that are suited to your location.

Ok, with that said, I would personally not be too concerned about the dormant season. Instead, I would focus on

• the frost free length of your growing season
• the total amount of heat you get per growing season. GDD is a good way to estimate this
• how many days and GDD it takes to ripen a crop of the varieties you want to grow
• what kind of sun exposure you will have after veraison to finish ripening the crop
• whether you will have enough heat left after harvest to harden off your canes
• if those two varieties can take the worst of the summer heat that you will get

Lastly, I think I would hedge my odds and plant 4 varieties or more, with a mix of long and short season varieties. You might want to pick a variety from a region in Italy or Argentina that resembles your local environment.

Good luck.
H

 

[Fox Squirrel Vin]

East of the San Francisco Bay does not have a winter as you know it. Temps get down to around 32F and that's about it. Frost happens about once every 20 years, except on the mountains. I moved from Ohio to California 40 years ago and found what you learned as a grower there does not apply here. It's the heat that causes problems.

I went from Colorado to Florida and 32 is rare here.. Having said that, last week of January I got down to 26, a hard frost, first in at least 10 years, maybe longer, and I lost half of a grove of mixed fruit TREES that were hardy to 30 degrees. All it took was one night so there is a lot of merit to what CortneyD says and a freeze after bud break can also be enough of a shock to kill the rest of the plant to the trunk or root crown.

Put 5-10 years of effort and growth into something and watch it vaporize in one day... You'll wish you did things differently.

 

[tmcfadden932]

I went from Colorado to Florida and 32 is rare here.. Having said that, last week of January I got down to 26, a hard frost, first in at least 10 years, maybe longer, and I lost half of a grove of mixed fruit TREES that were hardy to 30 degrees. All it took was one night so there is a lot of merit to what CortneyD says and a freeze after bud break can also be enough of a shock to kill the rest of the plant to the trunk or root crown.

Put 5-10 years of effort and growth into something and watch it vaporize in one day... You'll wish you did things differently.

Temps in the upper teens for a short period won't harm wine grapes.

 

[Fox Squirrel Vin]

Temps in the upper teens for a short period won't harm wine grapes.

Yes and no, it depends on what stage of de-acclimation the plant is in and what kind of freeze event- Radiation or Advection with a combination of the two being the most deadly.

 

[tmcfadden932]

My observations re: plants and heat tolerances as a Master Gardener. I still recommend folks planting things hardy to the cooler end of their zone because, while temps are rising, we are still getting major cold snaps (and unseasonable ones at that) across the nation and even in areas that historically have not had these events. Planting at the top end of your growing zone means those plants may not survive a poorly timed cold snap or cold-weather event (see much of Texas after the week's long winter weather). If you plant cool-adapted plants you can more easily mitigate hot weather events (shade cloth, extra watering, strategic pruning) than you can mitigate cold snaps. Or you shoot the gap and go for something thats puts your growing zone in the middle of its recommendation. But that's my plant-forward line of thinking that prioritizes plant health and survival- it isn't a fruit-production based recommendation. Just my 2 cents!

Wisconsin and California are two different climate extremes. Where you live the cold that comes out of Canada can go well below 0 degrees F for days at a time. In the last 4 decades, I have experienced only one event here in California's Central Valley where it went below 20F for days at a time, that was in 1990. Normally we have the Sierra Nevada Mountains shielding us from those cold blasts that come from the north that you get. We have the warming influence of the Pacific ocean.


https://www.goodfruit.com/predicting-cold-hardiness-of-grapes/

 

[tmcfadden932]

Yes and no, it depends on what stage of de-acclimation the plant is in and what kind of freeze event- Radiation or Advection with a combination of the two being the most deadly.

https://www.goodfruit.com/predicting-cold-hardiness-of-grapes/