Author Topic: Getting ready for winter, container citrus and lighting questions  (Read 2955 times)

franklazar26

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Getting ready for winter, container citrus and lighting questions
« on: September 29, 2019, 10:38:35 PM »
I'm preparing for the winter in the north now that nightly temps are dipping below 45 at times and have my citrus indoors at all times now. They're in the closet with a 125watt full spectrum grow light (bulb) and a germinating mat for heat. I have a calamondian planted from seed roughly 4 months old, a Flying Dragon, and soon to add some other trifoliate orange, along with my other mangos and pomegranates (not as concerned about those though). I was wondering if that was sufficient to keep the trees out of dormancy and continue growth? Should I add more lights? More wattage? What might give better results?

lebmung

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #1 on: September 30, 2019, 06:29:53 AM »
Bad idea, low light and warm temperatures.

franklazar26

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #2 on: September 30, 2019, 07:23:41 AM »
Bad idea, low light and warm temperatures.

What type of light would you reccomend? How many watts or should I just add a few more bulbs to it? Or just one larger one?

lebmung

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #3 on: September 30, 2019, 08:23:41 AM »
It's not about watts. Probably 1600 umol/m2s to sustain continuous growth and fruiting @25C it's a whole debate and nobody has the exact answer.
Mangoes need a lot of light otherwise they will die. Perhaps the cold hardy citrus should stay outside.

franklazar26

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #4 on: September 30, 2019, 08:36:47 AM »
It's not about watts. Probably 1600 umol/m2s to sustain continuous growth and fruiting @25C it's a whole debate and nobody has the exact answer.
Mangoes need a lot of light otherwise they will die. Perhaps the cold hardy citrus should stay outside.

The cold hardy citrus arent cold hardy enough for my area haha, last winter we saw temps as low as -45 F (-42 C). I'm not too concerned about mangos, more so my citrus as I usually give away the mango seedling after its started. I just dont like to waste seeds when I eat the fruit. But okay thank you for the tips though! I'll search for a light with that output. Thank you!

franklazar26

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #5 on: September 30, 2019, 08:56:00 AM »
So with my calculations I'm sitting at around 400 umol/m2s in a few concentrated spots.. looks like ill buy more lighting. Any particular that anyone would reccomend?

brian

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #6 on: September 30, 2019, 09:30:51 AM »
I'm curious what the best lighting option is also.  I am thinking about keeping some seedlings under grow lights in my basement this winter instead of in my greenhouse.

Last I checked - almost a decade ago - fluorescent was the best option.   I don't know if LED grow lights exist yet. 

franklazar26

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #7 on: September 30, 2019, 09:40:48 AM »
Currently I have 2 LED full spectrum bulbs (one 125w and 1 28w) which worked well in the past. It worked well for seedlings that I grew to give away and Very energy efficient and effective enough. I have been told in the past using almost like a "shop light" with a T-5 bulb is the most powerful and energy efficient, but I do not have the room in my plant closet for a 3 ft light, nor would I have a happy wife haha. I just need to find something more now that I have some permanent plants that I want to continue growth as it would during the summer or so.

brian

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franklazar26

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #9 on: September 30, 2019, 07:03:37 PM »
That one looks really good compared to what I can afford. I will have to ask my wife for christmas haha!

Millet

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #10 on: September 30, 2019, 09:24:42 PM »
brian why don't you just grow your seedling in your greenhouse?

brian

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #11 on: September 30, 2019, 09:39:14 PM »
Im going to take the seedlings that I have more than one of and put half in greenhouse and half in my basement under grow lights.  I am curious which will grow faster.

Vlad

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #12 on: September 30, 2019, 10:23:59 PM »
I have to overwinter my trees indoors and am thinking about putting them in the cold and dark. By cold I mean 45 to 50F. But how much light is there in dark, i.e., how many lumens are necessary to maintain the trees? I would like to keep them in a state of sem-dormancy.

lebmung

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #13 on: October 01, 2019, 06:37:28 PM »
Im going to take the seedlings that I have more than one of and put half in greenhouse and half in my basement under grow lights.  I am curious which will grow faster.

It depends on temperature.
If greenhouse is at 50F at most they will go into dormancy.
The one in basement will be weak and leggy. Lose some leaves as well. They might flower and then abort the fruit.

lebmung

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #14 on: October 01, 2019, 06:40:24 PM »
I have to overwinter my trees indoors and am thinking about putting them in the cold and dark. By cold I mean 45 to 50F. But how much light is there in dark, i.e., how many lumens are necessary to maintain the trees? I would like to keep them in a state of sem-dormancy.
 
They can take dark for two weeks after which they will drop the leaves.
You would need a window of 20% the surface of the room for cold and light..
Lumens are a bad indicator.

franklazar26

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #15 on: October 01, 2019, 08:14:30 PM »
There is however conversions online from lux to PPFD. Then there are apps that actually measure light in lux with the front camera. There are different conversions depended on the fixture you use or use of sunlight, but full sun is considered around 108,000 lux. With my current set up, I have a lux of 25,000 from two different lights, which through calculations it ranges anywhere from 300-450 PPFD. Iebmug said before for full growth PPFD should be around 1600 (I believe full sun is around 1800PPFD). I'm finding it is super hard, and very expensive to replicate full sun.. it's better off to just allow dormancy almost unless you have the funds and a mini greenhouse to allow for optimum growth. However my question is, citrus are recommended to have 8-12 hours a day under full sun, so if I have lower PPFD lighting for longer periods of time, say 20 hours, or 18 hours, would that compensate some or would it further stunt the plant by not giving it a dark period?

SeaWalnut

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #16 on: October 01, 2019, 08:55:27 PM »
Lumens measure the whole spectrum of the light with all the colors .
What you need for a grow lamp is a PAR meter wich is basically just a luxmeter that has 2 colored filters ,one blue and one red,and it measure the light intensity only of blue and red colors from the spectrum.
Its an expensive tool usually but one could borrow one from friends or a club with plant enthusiasts.
In order to see if your LED fixtue lost intensity,then a cheap lux meter can tell you that.

lebmung

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #17 on: October 03, 2019, 06:30:16 AM »
if I have lower PPFD lighting for longer periods of time, say 20 hours, or 18 hours, would that compensate some or would it further stunt the plant by not giving it a dark period?

Another bad idea.
Just let them sleep during the winter, unless you have limes which fruit and flower every month. But then, they are cheaper in supermarket so you need to have a big tree to compensate the cost.

franklazar26

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #18 on: October 03, 2019, 07:25:48 AM »
Alright, that's the answer I was searching for, just learning as I go. Thanks for your help Iebmung!

Vlad

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #19 on: October 03, 2019, 07:53:19 AM »
lebmung, you said: You would need a window of 20% the surface of the room for cold and light..
What do you mean b 20% the surface of the room? I am trying to determine the minimum amount of light required to keep the trees dormant and alive.

lebmung

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #20 on: October 03, 2019, 08:13:27 AM »
You welcome franklazar26

lebmung, you said: You would need a window of 20% the surface of the room for cold and light..
What do you mean b 20% the surface of the room? I am trying to determine the minimum amount of light required to keep the trees dormant and alive.

For a 10 sqm you would need a window of 2sqm facing south.
Most of homes in Europe have a 10% rate as a minimum architectural standard.
Keep temp no more than 15C, except for tropical citrus.

LemonLimeOrange

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Re: Getting ready for winter, container citrus and lighting questions
« Reply #21 on: July 16, 2020, 11:35:33 AM »
The sun is 10,000 Lumen per square foot. You need 2500-5000 lumen per square foot of artificial light to actively grow. Look at the Spectrum King Lowpro Flower or the Gavita Pro 1700e LED or LUXX 645 LED PRO. Indoors a germination pad will raise the micro temperature around the plant. Depending on your humidity indoors it can cause a stressful VPD which leads to a lot of lot of leaf drop. Low light and warm roots are  a very bad idea.