Tomato Lighting Time
 

This is starting them from seed and growing them inside until plant out time. Over the years here at Tomatoville - I have read a lot of opinions and advice on how long to keep your tomato plants under lights, and why it is important for the plants to get some dark time as well. I have seen every year that I have started tomato seeds inside - that there is a whole lot of growth while those lights are off.

I want to try something different in late January - (My tomato seed starting time.) I'm thinking of using the lights on for 12 hours and then dark for 12 hours. My reasons for trying this schedule are from experience, but I can also see this lighting schedule fitting with people's routines as well. We're told that we need 8 hours of sleep. That's 8 of those 12 hours of darkness. I know that some people work at night and sleep in the day. This lighting schedule would still work. Plants growing inside do not know when the sun is shining if you are growing them with lights.

I left a whole lot out - especially why it's important for the plants to get dark time. It's almost 2am, and I've tried everything else to get sleepy. I thought that maybe if I read some threads here - that reading would help, but it actually kept me awake. So here I am writing, and finally something is working.

What do you think about the 12 on - 12 off lighting schedule?

I use 12 on 12 off and have had good luck in the past. I don't think this is a magic number. I have a simple timer, so it's pretty much set it and forget it.


I think ambient temps and humidity are also important in early plant development.

Robert, I've always used the 10 on and 14 off to reduce stress on the plants during the winter. I've overwintered tomatoes and peppers and find that it allows them to store lots of energy. I also make sure the growing pot is larger than normal springtime pots to allow more room for the root network.

But, you have to think about having too large a pot that would possibly encourage the plant to go into full growth mode. This past season, I did a small study on when potting up is in a critical mode. Results were good and I still have one plant emerging from being what I would normally call "root bound". Marsha and Karen will find it nice to know that the one variety that has lasted the longest is their "Karma Pink".

Sadly, because of my second degree burned right hand, I will have to abandon the plant and put all my energy into healing. But, the bottom line is that you must control the area available to the plant to make an expanding root base. This stunts the overall size, and allows you to scale down fertilizers keep the plant healthy without allowing too much size expansion.

I hope this finds you "high and dry". I worry about all of our associates out there in the Lone Star State.

Signed: An old Tennessean with Davy Crockett sentiments and values. I had three cousins (they were brothers) who left Tennessee and traveled with Crockett, ending up joining with Sam Houston and helping with the total butt whipping of Santa Ana at the battle for San Jacinto.

Well, why don't you make it into an experiment, assuming that you have the facilities. I've mostly read 15 on, 9 off and that is what I typically do, but maybe you could start a couple of varieties 12/12 and another set of the same varieties at something significantly different, and then monitor for stretching, stockiness, etc. I've always had stretching with IND varieties, and little or none with dwarfs and micros. And cherry toms seem the worst of all at stretching.



Good luck!

Adding to my first post - the dark time is needed to complete the cycle of photosynthesis.

Greatgardens, I wish I had the extra heated area to do this experiment again, but our extra room is being used by our son and family. I did an experiment a couple of years ago when the room sat there being unused otherwise. I used 16 hours of light on to 8 hours of darkness. What I saw in the seedlings/plants is that they did grow but not as fast as those that were growing in another room - which I'm going to explain in my reply to what Ted wrote.

Ted, 10 on and 14 off is close to what I have been doing for the past few years. That is generally speaking because some days were 11 on to 13 off, and other days it was 9 on and 15 off - depending on when I woke up and when I turned the lights on and off. In other words, I casually/lazily monitored light to darkness ratios.

Mike, I'm glad to read that the 12 and 12 works for you. To me, it seems like 12 and 12 would work with people's schedules better without it hurting the tomato seedlings/plants. The usage of a timer in all cases would make things easier. I try to keep my house at 74F year round. We as humans like that, and so do tomato plants.

All of what I have written above is about when you have to start tomato seeds inside and raise them inside until planting out time. There are many other variables.

[QUOTE=ContainerTed;717969]Robert, I've always used the 10 on and 14 off to reduce stress on the plants during the winter. I've overwintered tomatoes and peppers and find that it allows them to store lots of energy. I also make sure the growing pot is larger than normal springtime pots to allow more room for the root network.

But, you have to think about having too large a pot that would possibly encourage the plant to go into full growth mode. This past season, I did a small study on when potting up is in a critical mode. Results were good and I still have one plant emerging from being what I would normally call "root bound". Marsha and Karen will find it nice to know that the one variety that has lasted the longest is their "Karma Pink".

Sadly, because of my second degree burned right hand, I will have to abandon the plant and put all my energy into healing. But, the bottom line is that you must control the area available to the plant to make an expanding root base. This stunts the overall size, and allows you to scale down fertilizers keep the plant healthy without allowing too much size expansion.

I hope this finds you "high and dry". I worry about all of our associates out there in the Lone Star State.

Signed: An old Tennessean with Davy Crockett sentiments and values. I had three cousins (they were brothers) who left Tennessee and traveled with Crockett, ending up joining with Sam Houston and helping with the total butt whipping of Santa Ana at the battle for San Jacinto.[/QUOTE]

Yes, I am happy to read about KP.
I hope your healing period is short and as painless as possible.

Stretching=not enough light.
If you can get about 100 watts light per square foot on the plants they wont stretch enough to amount to anything.
I do this by using a 27 watt CFL 65K that is = to 100 watt about every square foot.

Now look at your maximum daylight for a tomato plant in the area close to where it came from.
Mexico city 13 hours 18 minutes longest day
Equator average 12 hours all year long.

Tomato is a plant from equinox area (Peru, ..). Genetically they are customized 12 hours a day. Of course, they grow faster on longer days. :D
Vladimír

I do 16 hours on 8 off. not precicely on a timer, I just turn them on when I get up about 7-8 and shut them off when I go to bed generally 11-12 at night.
I agree with Vladimir that the longer "daylength" helps them grow faster. There is no comparison to any indoor lighting to natural sunlight and I find that leaving the indoor lights on longer helps to make up for the lesser overall lumens and the artificial spectrum. Where possible, setting lights up in front of a large south facing window to take advantage of what natural sunlight comes through along with supplemental 16 hours/day of additional artificial light seems keep plants growing properly in my situation in winter. even with good artificial light on them 16 hours per day, the seedlings still grow toward the window where mother sun is. I turn the plants regularly or they would lean noticeably toward the natural light. turning keeps them growing evenly.
KarenO

The following is taken from the book "Greenhouse tomatoes,Lettuce & Cucumbers" from the folks at Michigan State University.

Tomato plants started during the late fall or winter months should be exposed to as much light as possible during normal daylight hours. Artificial lights, if used, should be employed only during the daylight hours on dark cloudy days, and should not be used at night to extend the length of day.
The tomato is a facultative short day plant which flowers and fruits earliest if the day is not extended beyond twelve hours by artificial light. Young tomato plants do not need the light intensities of full sunlight.
If days are short (nine hours of light), the tomato plant will flower earlier and form the first cluster after fewer leaves than if day lengths are twelve or eighteen hours. An increase in light intensity also hastens flowering.


Ami

In June & July the plants will receive about 15 hrs of sunlight (up here in the NE USA), so that would be the number I shoot for... 15 on / 9 off

There is a lot of good information happening. Thank you.

Here in this part of Texas, there are days in February and early March where I can put the new plants outside in a wind sheltered area. That's one of the variables that I mentioned in post #5. Today, I will be getting a table set up for doing that. If it turns out to be a colder than usual winter - then they will have stay inside.

Here in January and February, you can toss the temperature averages out the window. It can be as cold as 10F -12C or as high as 80F 26C on any given day. That means moving plants in and out a lot, but you do whatever is best for the plants.

When I read this thread title, I was thinking of something like Burning Man; the Lighting Up of the Tomatoes...

[QUOTE=AlittleSalt;717961]This is starting them from seed and growing them inside until plant out time. Over the years here at Tomatoville - I have read a lot of opinions and advice on how long to keep your tomato plants under lights, and why it is important for the plants to get some dark time as well. I have seen every year that I have started tomato seeds inside - that there is a whole lot of growth while those lights are off.

I want to try something different in late January - (My tomato seed starting time.) I'm thinking of using the lights on for 12 hours and then dark for 12 hours. My reasons for trying this schedule are from experience, but I can also see this lighting schedule fitting with people's routines as well. We're told that we need 8 hours of sleep. That's 8 of those 12 hours of darkness. I know that some people work at night and sleep in the day. This lighting schedule would still work. Plants growing inside do not know when the sun is shining if you are growing them with lights.

I left a whole lot out - especially why it's important for the plants to get dark time. It's almost 2am, and I've tried everything else to get sleepy. I thought that maybe if I read some threads here - that reading would help, but it actually kept me awake. So here I am writing, and finally something is working.

What do you think about the 12 on - 12 off lighting schedule?[/QUOTE]

Robert, I find when I have insomnia the best thing to do is get up outta bed, start a load of laundry or do some dishes, fix a cup of herbal tea, and sit on the couch with a book. (Chamomile is the typical one suggested but California poppy, passionflower, lemon balm, valerian, and lavender all have calming properties.)

Before I know it I'm half asleep and ready to go back to bed. :yes:

Do you use a smart phone? Tablet/iPad or computer? Look for a night screen setting or app to install...the blue light of screens keeps you awake. Yellow tinted glasses help too if you have to drive or work under flourescents at night and the lights bother your eyes or give you insomnia later.

As for the tomatoes I have always had the lights set on a 12/12 cycle. My parents did it that way. Everything I have read says that's about right (reccomendations for things I start inside go from 10 to 16 hours on...12 was the middle ground for most things I grow.) Occasionally they end up with 14/10...if they're growing on the same shelf as some flowers I want to bloom early. :lol:

They also seem to do fine on the onion shelf...that has 10/14 on/off timer.

[QUOTE=amideutch;718139]The following is taken from the book "Greenhouse tomatoes,Lettuce & Cucumbers" from the folks at Michigan State University.

Tomato plants started during the late fall or winter months should be exposed to as much light as possible during normal daylight hours. Artificial lights, if used, should be employed only during the daylight hours on dark cloudy days, and should not be used at night to extend the length of day.
The tomato is a facultative short day plant which flowers and fruits earliest if the day is not extended beyond twelve hours by artificial light. Young tomato plants do not need the light intensities of full sunlight.
If days are short (nine hours of light), the tomato plant will flower earlier and form the first cluster after fewer leaves than if day lengths are twelve or eighteen hours. An increase in light intensity also hastens flowering.


Ami[/QUOTE]

Very interesting! I'm going to do an experiment this next year and test that out. One tray at 9/15 on/off and one at 12/12 on/off. And for fun myabe a tray at 18/6 on/off.