grow lights

[Powder]

This weekend I am planning on starting to grow my crab apple seeds that I saved from this fall. I put them in a moist paper towel and then they went in the garage fridge for the winter. They definitely froze while out there so I hope that doesn't matter.

I have a 4 foot shop light that I was planning on using as a grow light. Do I need a special type of bulb for that and if so, what kind?

 

[John-W-WI]

You need "full spectrum" blubs. Some colors promote flowers/fruit, other colors promote vegetative growth. A full spectrum will get them going. Some heat under them will help too.... Just a quick search on amazon turned these up (not the ones I have used, just looking for an example):

https://smile.amazon.com/Sylvania-2...290&sr=8-4&keywords=4'+flourescent+grow+light

https://smile.amazon.com/Hydrofarm-...d=1486179408&sr=8-3&keywords=growing+heat+mat

Hope that helps,

-John

 

[yoderjac]

This weekend I am planning on starting to grow my crab apple seeds that I saved from this fall. I put them in a moist paper towel and then they went in the garage fridge for the winter. They definitely froze while out there so I hope that doesn't matter.

I have a 4 foot shop light that I was planning on using as a grow light. Do I need a special type of bulb for that and if so, what kind?

Nope. I grow a lot of tree seedlings under shop lights. Spectrum is more important for plants that spend a long time indoors. For seedlings, only a tiny fraction of their life is spent under lights. I've played around with expensive lights and found zero difference in growth. What is much more important than the wavelength is the amount of light. It is typically expressed in lumens. I hang several two bulb shop lights next to each other. Light energy diminishes with the distance squared. Expensive lights are often hot. They put out more light but need to be kept further from the trees. Fluorescent shop lights are cool and can be rigged so you can adjust the height just 2 or 3 inches above the trees.

The expensive bulbs come with a spectrogram that shows how much light is produced at each wavelength. They are overkill from my perspective for starting trees. When you buy the cheap bulbs at Lowes you can buy different colors (wavelength). These numbers are really an average. I've tried mixing different wavelength bulbs and again seen no change in results. If you are just running a few lights this is fine. I run 30 or so shop lights so cost becomes a factor. I now use a single wavelength bulb rather than mixing because I can buy a full box of bulbs cheaper.

The most important factor is the amount of light. Using more shop lights is better. Using Express trays helps because you can reorganize the cells tallest to smallest and adjust the lights at an angle to keep them close to all trees. Finally, set your timer for 15 hour days. Artificial light is not as intense as sunlight but you can compensate to some degree by longer days.

Here are a couple Wickson crabapple seedlings I started in early December under lights:

They were recently transplanted from 18s into these 1 gal RB2s. There are shop lights just above them out of the picture. You can see the lights in the background to get an idea of spacing between lights. They are positioned just above some 5" roottrapper bags with yellow twig dogwood cuttings.

Thanks,

Jack

 

[yoderjac]

Jack,

I told you that a few times a long time ago. Lol

Save your money and get a cheap shop light. Yeah a fancy expensive tube light might make a small difference but, not enough to justify the extra expense. You're catching on. I wouldn't waste the electricity or the money on a fan either. If you do you'll spend more on contraptions than just buying rootstock or seedlings.

Must have been a long time ago. I haven't used anything but shop lights for a long time. As for a fan, I think there is something to be said for stressing young trunks but it is not a first order factor for sure. It can also cause problems if you run it too much. When I use a fan directed at seedlings, I only run it for about 15 minutes a day. A couple years back, I got a whole house atomizing humidifier and instead of venting it into my heating system, I vented it directly into the basement which is where I grow. I was getting condensation and dripping so I got a large oscillating fan and put it across the room pointed centered at the humidifier output. As it oscillates, it distributes the mist before it can condense. This provides enough general air movement in the room that I don't use the fans directed at seedlings as much.

Thanks,

Jack