Switching to LED lighting for winter

[Hoops]

I've previously used traditional fluorescent T5 grow lights (6500K) for overwintering my tropical plants. Considering moving to LED lights this year. At what distance should LED lights be from the plants? I've found conflicting info on this. Any advice appreciated.

 

[Glaucus]

Depends on the light and on the plants. Any reasonable LED will have a map with photosynthetic light intensities for a given height.

 

[hemmy]

At what distance should LED lights be from the plants? I've found conflicting info on this. Any advice appreciated.

What size and wattage are the LED? My 3x 300W spider farmer setup sets at the highest distance for my setup and comfortable shelf height. Which is 2’-4’ above the foliage of my variously sized ficus trees. Last year was 3rd year for growing indoors and I was at 40-50% dimming last year. They seem to do much bettter this year, than the first year when I blasted them on 100%.

 

[Hoops]

My plant space is 2 ft. by 4 ft. Looking more closely, I see that some lights do include this information in their advertising.

 

[BrightsideB]

A lot of lights have a lighting area in the shape of a square. I’ve seen long rectangular led setups. If that is what you have. I’d look around for something like that. Otherwise you’re wasting the light. And more powerful lights generally mean you need them further from the light source in a sense wasting potential and more blinding. I use HLG and they are bomb!

You will also most likely need to do trial and error based on the space from the foliage and light. If I knew the right light I’d share. But going with a light that is square won’t help a longer rectangular setup unless you have two. And most cover 4’x 4’. Try finding something with 4x2 feet if possible. And also more powerful than your t5. Since I guess that is why you want to switch.

 

[LeftHandLuke]

You will also most likely need to do trial and error based on the space from the foliage and light. If I knew the right light I’d share. But going with a light that is square won’t help a longer rectangular setup unless you have two. And most cover 4’x 4’.

This is probably the best advice on the topic. Most recommendations from sellers/manufacturers are specific to things like seedlings or various stages of things people grow indoors (cannabis, etc.) -- useless when it comes to trees of varying heights, widths, growth stages and species. I've used this light for the past 2-3 winters. Trees sitting on shelf in basement, light hanging from ceiling 2-3 feet above top of tallest trees. It covers a 2'x4' space nicely with a bit of overhang that allows for some plants to be placed on the floor nearby to collect some diffused light. Some trees that need less light are placed in the "shade" of the taller ones. I like this light because of the dimmer switch. Trees/plants I'm wintering include dwarf pomegranate, lemon, ixora, bougainvillea, portulacaria, adenium, BRT.

 

[Hoops]

Thank you for the responses. I'm going to try a rectangular LED panel (with dimmer) designed for 4'x2' growing space.

 

[Kievnstavick]

As meantioned, any reputable grow light seller/producer should put the light intensity map and height onto their product page.

You can use this info to find what works best for you.

I found keeping my lights about 18-24" above my average plant height is a good middle ground for the shelf dedicated to my largest plants. It balances light intensity, plant growth, and reduces how many times I need to prune/adjust my light height.

I have a shelf for smaller plants and seedlings that sits around 12" from the average plant height.

My Schefflera bonsai has the light sitting 8" above the highest point of the tree.