I think I’ve got everything right, but I wanted to double check… what indoors temps are suitable for sweetening my citrus indoors?
One guide you might use is what the temperatures are in good citrus areas. I’ve run my greenhouse by mimicing temperatures in the central valleys of CA. What you find is that it doesn’t take warm winters. Hot summers and cool winters work fine. Winters there run 55-60F by day and 38-40F at night on average. My navels at those temperatures sweeten in January.
The problem people run into with indoor citrus is getting the right balance of temperature and light, maybe humidity. Many growers end up with citrus that defoliate.
What would happen if you kept your greenhouse heated to 80 all winter?
I’m using grow lights combined with heat mats to keep my temps at a constant 80. They do really well, but I wonder if they need some kind of colder period.
That’s probably won’t work for him because most of stone fruits need chill hour to produce fruits.
Tony
I’d go broke…!! That would probably cost $1500-2000 per month.
No citrus don’t need any cold, ie chilling. But it’s possible that the fruit might taste better with cool winter than with warm.
If your setup is working good I’d stick with that.
And yes I’ve gone cool in winter to get chilling on the other trees.
Wonderful. Thank you. That’s some good piece of mind.
I have a large Washington navel in the backyard, and my summer daytime highs average about 90F. Our winters are 58f high and 40f lows. And the oranges my tree produce are super sweet - think orange soda.
They ripen late Jan - April so the heat requirements are met throughout the summer months, and they just fatten up and change color fall/winter
Steven,
Last question. What is this chart referring to? Summer heat? There’s a “needs heat to sweeten fruit column.” https://www.fourwindsgrowers.com/our-citrus-trees/citrus-variety-info-chart.html
Guess you didn’t read my post lol
I did, but that chart is very misleading. I could assume that it’s referring to summer heat, but I want to be sure.
And don’t take offense! I ask a lot of stupid questions, so I can 100% correct. I appreciate your response, @Calron.
No problem. To answer the question it is the summer heat that’s important. For example, I’m located 30-40 miles east of San Francisco and can grow large very sweet navel oranges. But in SF they don’t stand a chance due to the lack of summer heat. However they do grow lemons without issue as the bitter citrus does not require the heat. (I grow lemons just fine as well).
So someone like myself is gonna have problems growing oranges near Philadelphia? 
What if I were to supplement heat in the winter time? Or does that not matter one bit? Or perhaps lengthen my summer by bringing them indoors early with supplemented heat.
I think you should be fine. Just try to get at least 6-7 hours sunlight per day. The winter temps I don’t think are that critical. My winters are cool, and they ripen just fine.
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I’ve always found the satsuma mandarins start tasting really sweet once the temperatures drop. Maybe it’s just a coincidence since they are ripening around the time the temps drop but it doesn’t seem to hurt at all for sure.
Yes that’s talking about summer heat. The fruits that are acidic like lemons don’t need a warm summer. Things like Navels that sweeten up as acid declines and sugars increase need a warm to hot summer.
Remember this is for CA conditions. So they are in effect telling you which need inland heat compared to which citrus will do well with a coastal influence. Inland areas have 90-110F summer heat. Coastal areas mainly stay in the 60s, 70s, and 80s for highs.