Grafting Indoors Under LED Lights

Here’s what I’m doing since I have no more room in my greenhouse. For $120 dollars I put this together.


Grafts are tented with lightweight poly. Heat mats line the bottom of the tubs and are between a layer each of aluminum insulation with a layer of cardboard first put down on the floor.

I did 150 pecan/hickory/hican grafts or more; 30 persimmon I suppose; have a dozen pawpaw saved. Many-many pecan ‘Hark’.

I have 3000 lumen LED bulbs. A total of four. These will do the job until I can take the grafts outdoors after frosts.

This tub is all ‘Hark’ pecans

I bought beeswax to finish the job. I’m using 50/50 beeswax to paraffin.



Tomatoes/peppers I transplanted on March 1st to 32-cell rootmakers under 1600 lumen LED’s


My work area.


Very nice!

Are those straight up LED bulbs? And do they work as grow lights?

I did a (tiny, tiny, tiny) bit of research a while back and I was led to believe that LEDs didn’t work as grow lights.

Great for grafting, but terrible for growing on after the graft.

Plants respond to WATTS within a given spectral density.

When considering LED systems, notice the actual Watts and not the watt-equivalent-to-incandescent-lights.

Along these same lines, notice that Lumens are a measure of human perception and not plant requirements. Plants don’t have eyes! In particular, Lumens are computed from the intensity of green spectrum in a light source – a frequency that most plants ignore!!

I’ve never had tomatoes this thick-stemmed and it’s all due to LED’s. Sure they’re great bulbs for growing. From what I heard from a company chatting back and forth on ebay, they’re evolving almost daily. For this grafting set-up I chose 24w 3000 lumens. I was told an 8’ LED puts out more energy than (2) 4’ bulbs but I chose to stay with 4’ bulbs. This is a good situation for me.



Very nice.

Nice! Is that a roll of mylar that you have draped to create your tent? You pulled your setup together at a fantastic price!

I’d love to have an actual, practical, work area. I have to usurp the table or a counter, or sit outside on the ground, instead. Of course, that means I have to clean up my messes as soon as I make them, and put everything away in between uses. Your operation looks very efficient.

I don’t sell lightbulbs or light fixtures, but I do contract for consulting with multi-million dollar indoor growing firms: fruits, vegetables, cannabis, you name it. If your tomatoes look better than they did before then what you were using previously must have been pretty poor. Regardless of improvements in LEDs, the bottom line is that plants respond to real watts in a specific spectral density.

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Bart, LEDs work very well as grow lights when they are emitting light in the necessary spectra for plant use. One of the main reasons I put up a grow tent was because mine were lighting the neighborhood with a magenta hue.

Go ahead, price out an LED system with 65-75 Watts/sq.ft. projected area with 6500 Kelvin spectral density.

I don’t know if you actually meant to reply to my post or not, Richard. My lights work very well for me. I’m not pulling one down and getting out a magnifier to read the spectrum for each diode in there. I did investigate before purchasing a few years ago, and wound up getting arrays that are frequently used in cannabis production. I do know that they are 300 watts per 4 sq ft. effective area, and each cost more at that time than Barkslip’s entire setup. I use them in conjunction with HO T5’s which are 6500 range. Eye protection is a necessity when entering my tent.


A good choice. LED’s are by nature, single-spectra. We use arrays of them effectively in commercial growth of baby kale, lettuces, etc. at 30 Watts/sq.ft. projected area. But for the application in this thread they do not make sense in the long run.


Plants respond to light energy. Light energy diminishes with the distance squared. This means hanging cool likes close to plant (2 to 3 inches) can provide light than a higher wattage hotter light that must be kept further away to keep from frying the pant. I use fluorescent bulbs for starting seedlings in the winter and they work great. I would expect that would be the same for LEDs. Lumens and the distance the light can be kept from the plants are a better measure of energy output than watts. True, it is limited to the visible spectrum, but it is a measure of energy output. Watts is the measure of energy consumed. So, a hot light is consuming many more watts but much of that goes to heat. At least for starting trees, they are outstanding. Keep in mind that trees started indoors in the winter are spending a small fraction of their lives under artificial light.

Just as an example, I started a chestnut under lights between Christmas and New Year. When I planted it in early October, it was over 6’ tall and 3/4" in caliper. That early start under lights really helps.

The only reason I have not tried LED lights is the cost. Early on there was a format issue, but now that they make them in shop light format where it is easy to keep them adjusted a few inches above the seedlings, the only reason I see not to use them is the initial cost. That will keep dropping over time and as my fluorescent ballasts die, I’ll probably replace them with LEDs.


Yes. In terms of physics, it’s measured in Watts per spectral density. Quoting the inverse squared law does not contradict the fact that many crops (as stated above) perform best at 65-75 W/sq.ft. projected area at 6500K spectral density while others can achieve optimal performance at other spectral fluxes.

@MuddyMess_8a Yep that roll of mylar cost 27 bucks w/shipping from Amazon. It’s 50" x 50’.

All this talk of lights is beyond me. I did this for efficiency because I have no more room in my greenhouse and I am certain that for a month, a month and 1/2, these lights will work fine. As a matter of fact, I used to graft and then keep the plants in complete darkness until they knitted and then carry the tubs into my greenhouse to provide light. The other half of my story is if I want to bring a few tables or one long table under them I can grow flowers/vegetables/ or anything from seed.

Muddy, that work area is wonderful. I graft a tree, dip it in wax and roll up the roots in a moist towel and continue grafting until the towel is full and then I heel them in in 3’s or 5’s or handfulls at a time depending upon caliper. Got my big tubs at an auction for five bucks.



Thank you.

Out of curiosity,what do you do with many of those trees?

I need to pay off a credit card and I bought a car that put me in debt 1800 dollars. I should be able to make at least 2000 dollars if not more.



I am interested in your grafting. What is the reason that some scionwood were totally wrapped an d some not?

Were your paw paws rootstocks in those long tube pots? They have so long tap root.