grow lights for winter indoor period

Do-it-yourself projects such as greenhouse or shadehouse builds and related topics.
ipdown
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grow lights for winter indoor period

Post by ipdown »

Hi all, not sure if this is the best place to ask this, but I don't have a place (yet) to build a proper greenhouse and will keep my small collection indoors. The room I plan to keep my plants will not be regularly heated, but based on experience the average temperature will be around 17-18 deg C.

The problem is that in this room the plants will see very limited daylight. Here is what I can do about that:
1. I have 8 pcs. small 6W fluorescent tubes I can use - for free, I have them.
2. Buy some blue-red chinese LED strip from aliexpress - between 10 and 50 EUR depends on size/length.
3. Buy a pair of automotive HID lights with ballast - about 25 EUR.
4. Keep the plants in dark room and hope they will not etiolate.

Note that 50 EUR is my max budget, and I will have to fit into it.

What would you do and what are your advices? Should I try providing them some artificial light and which of the three options
is better for the plants? Or should I keep them in darkness and relatively cold, hoping they will just "hibernate"?
Thank you for your ideas!
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anttisepp
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Re: grow lights for winter indoor period

Post by anttisepp »

Isolate them from room warm air and keep them at about 10C and totally dry, they won't grow till the spring.
I use grow lamps only for brazilian (Disco-Melo-Uebelmannia) cacti because our winters are very dark but these ones need higher temps and some watering.
ipdown
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Re: grow lights for winter indoor period

Post by ipdown »

Thank you Antti. Winters here in Bulgaria are milder, sometimes warm, with only few weeks being more cold. That particular room without heating temp can vary between 12-18 deg C, depends on outside temp and sun. In the extremes it can go below 10, would that be a problem? Mostly trichos, some mammillarias and grafted lophophora, also some very young seeslings from seed mix I don't know.
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mikethecactusguy
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Re: grow lights for winter indoor period

Post by mikethecactusguy »

How about t5 grow lights.?
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prickle
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Re: grow lights for winter indoor period

Post by prickle »

sounds like they should be outside for winter to me.
i am not an expert at all, i am still new to cacti myself. i also do not know what your weather is going to be like etc, so dont take only my word for it.

i have trichocereus and lophophora so i know a little about them, but i do not know about mammillarias.
trichocereus and lophophora will go dormant once they get down to 10°C and they will survive just fine, in fact that is an ideal temperature for them during winter.
you should keep them somewhere where moisture wont be a problem if that is something your local weather might throw at you, but it sounds like they might be better off outside.

if you put them in a dark room at 17-18°C they will etiolate. that temperature is too high for them to go dormant so they will keep searching for light. i have also heard that it is not best to prevent them from going dormant and they will grow better and even faster if allowed to sleep for the winter, but i have not verified that yet.

as far as artificial light goes, i would like to hear about this too. i have read about a lot of people who say it is not even close to enough light but i have also read about people who do keep cacti under a grow light, apparently successfully.
i have a bolivian torch that i want to stop from going dormant this year if i can, keeping it under a grow light did cross my mind. i have yet to find any information about the required lux, colour, etc so i am not willing to risk it yet.

if you do decide to go with a grow light option i would love to hear how it goes.

good luck
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Re: grow lights for winter indoor period

Post by esp_imaging »

anttisepp wrote: Sat Aug 22, 2020 7:01 pm Isolate them from room warm air and keep them at about 10C and totally dry, they won't grow till the spring.
Good advice
prickle wrote: Mon Aug 24, 2020 1:22 am sounds like they should be outside for winter to me.
trichocereus and lophophora will go dormant once they get down to 10°C and they will survive just fine, in fact that is an ideal temperature for them during winter.
you should keep them somewhere where moisture wont be a problem if that is something your local weather might throw at you, but it sounds like they might be better off outside.

if you put them in a dark room at 17-18°C they will etiolate. that temperature is too high for them to go dormant so they will keep searching for light. i have also heard that it is not best to prevent them from going dormant and they will grow better and even faster if allowed to sleep for the winter, but i have not verified that yet.
More good advice.

Frost free and dry will be very good conditions for them. For Trichocereus, depending on the species, regular frost and dry will also be fine.

Grow lights are often over-rated. Standard LED ceiling panel lights or LED light bulbs work fine, daylight or cool white are probably better than warm white, and you can often get sensible info on lumens output.

Extremely bright sun can be around 100,000 lux (lumens/sq metre)
10,000 lux is a bright day, maybe sun through hazy cloud.
2,000 lux seems a decent amount for small cactus seedlings.

So a 2000 lumen light covering 1sq m may be OK to start seedlings, or covering 0.2sq m may be OK for adult plants (or not enough light to grow them really hard).
Having the light close to the plants (only a few cm away) is most efficient, so easiest with large panels and seedlings and low or miniature plants, plus they benefit from the warmth of the lights. Using side reflectors (and a standard reflector with light bulbs) is important too, preferably silvered, but white is useful too.
A small diverse collection of Cacti & Succulents
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ipdown
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Re: grow lights for winter indoor period

Post by ipdown »

mikethecactusguy wrote: Sun Aug 23, 2020 11:13 pm How about t5 grow lights.?
I didn't even knew about this nomenclature, thanks, learned something new, found what T5 means here: https://en.wikipedia.org/wiki/Fluorescent-lamp_formats

In fact, the 8 lamps I have are marked: T5 6W 6500K. Each is about 25-30 cm long.
ipdown
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Re: grow lights for winter indoor period

Post by ipdown »

prickle wrote: Mon Aug 24, 2020 1:22 am sounds like they should be outside for winter to me.
I am afraid to do that, as the outside temps sometimes can go well below 0 C and stay there for days. Also, it is usually humid outside.
Last summer was warm, for example about 2 degC night - 10 degC day temps, but we also had few days with up to -10 degC.
prickle wrote: Mon Aug 24, 2020 1:22 am if you do decide to go with a grow light option i would love to hear how it goes.
good luck
I will let you know if I go this way, perhaps in a new thread. I can try both ways with using light only for some plants, and just keeping in cold others.
ipdown
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Re: grow lights for winter indoor period

Post by ipdown »

esp_imaging wrote: Mon Aug 24, 2020 9:36 am
Grow lights are often over-rated. Standard LED ceiling panel lights or LED light bulbs work fine, daylight or cool white are probably better than warm white, and you can often get sensible info on lumens output.

Extremely bright sun can be around 100,000 lux (lumens/sq metre)
10,000 lux is a bright day, maybe sun through hazy cloud.
2,000 lux seems a decent amount for small cactus seedlings.

So a 2000 lumen light covering 1sq m may be OK to start seedlings, or covering 0.2sq m may be OK for adult plants (or not enough light to grow them really hard).
Having the light close to the plants (only a few cm away) is most efficient, so easiest with large panels and seedlings and low or miniature plants, plus they benefit from the warmth of the lights. Using side reflectors (and a standard reflector with light bulbs) is important too, preferably silvered, but white is useful too.

The only lumens information from my list of options I posted is on the automotive xenon HIDs - each is rated 32K lumens, 35W, color temperature is variable, I guess cooler is better for the plants (higher color temp). I've used such HID bulb once as a work lamp - powered the ballast with an old 18V/2A psu brick from an old laptop. Most of the ballasts working voltage is wide enough.
I don't know about what spectrum plants likes most, but for me working on that kind of light was very close to daylight, and they are pretty bright.
If I go this way I will get cheapest universal xenons available, they are usually marketed as retrofit/conversion kits and are not car specific.
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mikethecactusguy
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Re: grow lights for winter indoor period

Post by mikethecactusguy »

the T5 lamps I use put out around 13500 lux at a 10" distance from the plant tops. Tested with a light meter. I used the space to protect my melo's during the colder months and to help grow stubborn plants as well as smaller cuttings and seedlings. Each fixture hold 4 -T54t5 tubes. 4100k 4300 lumens each.
I bought them last year on amazon for $65 each. I bought 2 fixtures Don't feel it was waste of money at all. The total light rating is for one fixture.
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ipdown
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Re: grow lights for winter indoor period

Post by ipdown »

mikethecactusguy wrote: Mon Aug 24, 2020 6:28 pm the T5 lamps I use put out around 13500 lux at a 10" distance from the plant tops. Tested with a light meter. I used the space to protect my melo's during the colder months and to help grow stubborn plants as well as smaller cuttings and seedlings. Each fixture hold 4 -T54t5 tubes. 4100k 4300 lumens each.
I bought them last year on amazon for $65 each. I bought 2 fixtures Don't feel it was waste of money at all. The total light rating is for one fixture.
Thanks. I've found yours on amazon. A lot longer tubes, fixture with nice reflectors, perhaps tubes spectre is also plays role. I will consider getting something like that in near future.
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anttisepp
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Re: grow lights for winter indoor period

Post by anttisepp »

Growing in southern Europe is very simple IMHO. Only some additional covering and some very small heating by thermocable. Not expensive, much healthier for cacti than winter growing under art. lights. You'll take a risk only with brazilian species, not other common ones.
Do you have a garden or balcony?
esp_imaging
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Re: grow lights for winter indoor period

Post by esp_imaging »

ipdown wrote: Mon Aug 24, 2020 2:37 pm
The only lumens information from my list of options I posted is on the automotive xenon HIDs - each is rated 32K lumens, 35W, color temperature is variable, I guess cooler is better for the plants (higher color temp). I've used such HID bulb once as a work lamp - powered the ballast with an old 18V/2A psu brick from an old laptop. Most of the ballasts working voltage is wide enough.
I don't know about what spectrum plants likes most, but for me working on that kind of light was very close to daylight, and they are pretty bright.
If I go this way I will get cheapest universal xenons available, they are usually marketed as retrofit/conversion kits and are not car specific.
I'm not sure how easy it is to get efficient general-use reflectors / diffusers for automotive HIDs. Producing a narrow beam is probably very unhelpful, getting a fairly uniform spread of light over (say) 1sq m is more likely to be useful.
A small diverse collection of Cacti & Succulents
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mikethecactusguy
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Re: grow lights for winter indoor period

Post by mikethecactusguy »

ipdown
to add to my t5 suggestion. As I said I used this arrangement to help sustain 24 cactus through the wet cold weather. Originally I was going to let the plants enter winter dormancy. A few weeks into the adventure I noticed a few had started to grow. I pulled out a light meter and realized the lamp output was high enough to support non-eloited growth. I continued with regular waterings and watched them all thrive. A few actually flowered early and my largest melocactus seeded.
Again I bought 2- 4 tube sets that came in a reflector bases. No issues with damaging anything. They did produce heat. My office temp stays around 24 centigrade. Around the plants the air temp raised to 30 centigrade.
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samreu
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Re: grow lights for winter indoor period

Post by samreu »

I also use T5 over the winter for certain plants. I use an Agrobrite fixture with 6 bulbs - 4 foot they are called but are actually 45" in length. I hang the fixture at 29" above the plants in a 2 x 4 foot setup, which has a white floor and white reflective walls (white hardboard) that are higher up than the lights so everything gets reflected onto the plants. I also have white wall at the ends but not as high as I have computer fans in the unit to keep airflow and keep the temps a little lower as it can get hot under the lights.
At the 29" height, I get a reading around 19,000 lux with 6 lights running, or 12-14,000 with 4 tubes running, obviously a little less as I get to the extremities. Temperatures run about 73F or 22.7C and then go back down to 65 at night which is the temp in that unfinished basement area.
I keep the plants in this setup dry, for the most part (November to March - located in Canada), maybe a little light water every 4-6 weeks depending on the plant.
I was happy with the result last year, it maintained the plants well with no real problems that I could assess. I ran 4 lights for the most part and then about the last 2-3 weeks before bringing the plants out I went to 6 lights.
I also put some plants in a north facing basement windowsill, no sun - the windowsill is about 8" wide so I keep the blind mostly shut but open enough to allow so air circulation - the room is at 69-70F but the window sill setup keeps things at 59-65F depending on outside temps - this setup also did well for me - everything was kept dry throughout the Nov - March period in the windowsill.
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