indoor propagation

Submitted by Klapwijk on Sat, 03/19/2011 - 09:41

Hello all,

at Mark McDonough's request, I'm posting some pictures of my propagation box and grow room, used mainly in the production of rhododendron and azalea cuttings and seeds.

Chris Klapwijk
NARGS webmaster
Surrey BC Canada


Submitted by Lori S. on Sat, 03/19/2011 - 10:08

Very impressive!  Looks like the lights over the big propagation box are raised and lowered on chains?

Submitted by Klapwijk on Sat, 03/19/2011 - 10:15

Hi Lori,

yes, they can be raised and lowered with the chains if needed, but most of the time the lights are 40cm/45cm (16"/18") above the plants.

Chris Klapwijk
NARGS webmaster

Submitted by RickR on Sat, 03/19/2011 - 21:11

Very nice set up, Chris.
I am a bit confused with the prop box.  Are those incandescent bulbs the only source of light?  I would think they produce a lot of heat.  Is there a reflective top?  What are the "chicken coup doors" for?

Submitted by Klapwijk on Sun, 03/20/2011 - 11:31

Hi Rick,

"I would think they produce a lot of heat" >>>> that's the whole idea.

I know two people (one now deceased) who had fires in their greenhouses as a result of malfunctioning heating cables.

One guy completely lost his greenhouse, the other was luckier: the heat generated by the fire melted the solder of his overhead watering line, rupturing it which in turn extinguished the fire.

For an indoor setup I needed something safer than conventional heating cables so I figured incandescent bulbs would do the trick.

Picture #1 shows the galvanized sheet metal top leaning against the back wall.

Temperature control: initially, I ran into a problem. I purchased a Johnson Controls A419 NEMA 4X,

The relay contact rating in a Normally Open setup is 16 Amp @ 120 Volts, the load is 8 x 60 Watts: 480 Watts / 110 Volts = 4.3 Amps

Yet for some reason the relay contacts would occasionally get stuck in the closed position and not de-energize the system resulting in the system overheating several times. They replaced the unit free of charge, but even the replacement unit did the same thing.

To lower the load on the temperature control relay, I connected the bulbs to an Omron MK2EP-UA-AC120 double pole, double throw relay, (Apparently, this relay is now obsolete, not surprising, I bought it about 25 years ago.)

To further reduce the possibility of the system overheating, I installed a second A419 NEMA 4X.

So, (are you still with me?) the primary control kicks in at 20°C (68°F) and energizes the Omron relay, which causes the lights to come on. The primary control kicks out at 21.6°C (71°F), de-energizing the Omron relay, which turns the lights off.

The second A419 NEMA 4X is set to cooling mode: should the primary control fail to kick out and should the temperature rise above the upperlimit of 21.6°C (71°F), the secondary control, which kicks in at 24°C (75°F), will cut the power to the primary. The secondary kicks out at 19°C (66°F), restoring power to the primary. The system has run flawlessly this way for the last 8 months

The fan runs 24/7 and minimizes the effects of radiant heat, which creates 8 distinct hot spots directly above the bulbs.

The 4 "chicken coup doors" give me easy access to the inside of the unit to replace any burnt-out light bulbs.

Chris Klapwijk
NARGS webmaster

Submitted by RickR on Sun, 03/20/2011 - 22:33

Chris, your method is explained very logically.  Understood, and clever with the second relay I might add.  I did notice the sheet metal standing up behind.  I am still very surprised that those light bulbs provide enough light.  Don't Rhododendron spp. cutting take relatively longer to root than other woodies?

Submitted by Gene Mirro on Tue, 03/29/2011 - 15:20

This is my fluorescent light growing setup:

I started with a 4' x 4' piece of plywood, and attached 1x2 sides to it.  I brushed two coats of polyurethane on it to make it somewhat waterproof.  I use white styrofoam insulation to reflect light back towards the plants.  The fixtures can be hung from a basement or garage ceiling, or they can be hung from a frame attached to the 4x4 base.  If you place the 4x4 base on a card table or folding office table, the height will be just right for comfort.  The lights are about 6 inches above the plants.

I keep the setup in a heated area of the house.  All waste heat from the fixtures goes into heating the house, so it's 100% efficient use of power.  And it's very convenient to get to.

For delicate seedlings  and new transplants, I recommend covering the flats, like this:

I get nearly 100% survival of transplants using this method.  And it reduces frequency of watering.  Also, it's the only way to keep tiny seedlings like Ramonda alive.  You can also use clear plastic bags that can be closed.  The pink bloom on the left is Mimulus lewisi.

I start slow-growing plants in December, and keep them growing all winter long.  They will sometimes bloom under the lights, and will often bloom the first year in the garden.  In the top photo, the lavender flower is Epilobium rigidum, blooming in about four months from seed.  I hand-pollinated it, and it set good seed under the lights.

Submitted by Lori S. on Tue, 03/29/2011 - 19:55

Excellent setups, Chris and Gene.  Those nice wide tables are the bee's knees!  

(Let's see... I could always tear out the furnace to make room for some good-sized tables, and then just heat the house with cans of Sterno... and then I could really start some stuff!  ;D ;D)

Gene, I use very similar clear plastic tray covers - they're very handy.  
For my (much more modest) set-up, I use a pair of 4' double fluorescents over each shelf, also suspended on chains.  I keep them as close to the trays as possible, and raise them as the plants grow.  

Submitted by Gene Mirro on Wed, 01/16/2013 - 16:00

For those of you using the cheap fluorescent shop lights, I discovered that a lot of them (at least in the old days) didn't come with a real ballast.  They had little bits of electronics and transformers and stuff sprinkled around which acted sort of like a ballast.  At $12 a fixture, you can't expect much.  The problem is that these fixtures are noisy, don't start well in cold temperatures, eat up lamps, get the picture.  They are junk.  About half of mine stopped working over the years.  I just bought a bunch of replacement ballasts at Home Depot and figured out how to install them.  They make all the difference in the world.  The lamps come on instantly without flickering, and there is no noise. 

There are a lot of different ballasts.  You will have to write down the type of lamps in your fixture, and bring it to the store.  If you are intimidated by wiring diagrams, don't try to do this.  It's a little tricky and quite time-consuming.  Taking the fixtures apart is a problem.  You could just buy the new energy-efficient fixtures.  I didn't want to do that because they don't fit well into my existing fluorescent light garden setup.

Submitted by Gene Mirro on Sun, 01/27/2013 - 13:29

My latest fluorescent light setup:

[attachthumb = 1]

It's in a corner of the kitchen, so no rafters to hang the lights from.  So I built a frame out of 1x2's that mounts to the 4x4 foot base.  I keep the lights about 4-6 inches above the plants.  This setup lets me move the lights up for easy access to the plants.  You can see the rigid foam insulation pieces around the edges that reflect the light back in to the plants.  You can also see the propagation domes, filled with moist air.

The whole thing sits on a 30 inch x 5 foot long office table from Office Depot, with some plastic film and bubble wrap on it to protect the table from scratches and moisture.  This places the plants at just the right height.

I keep my house cool during the Winter, around 60F.  At around 70F, the seedlings grow long and weak, and have disease problems.  For some seedlings, like European alpine Gentians, 60F is too high.

The fixtures are ancient 48 inch shop lights with two lamps per fixture.  Each of them has a new ballast in it, secured by the two bolts that you can see on top.  I use cool white lamps, with a couple of daylight lamps mixed in.

Submitted by RickR on Sun, 01/27/2013 - 17:41

I hear you about low grade ballasts.  What I really look for in a plant light fixture is a good, mirrored, reflecting cover.  If the ballast goes, I'll put in a new one and then it lasts "forever".

I am anxious to test out your tip about reflective sides, like you have with the rigid foam board.  Thanks.

Edit spelling error.

Submitted by Gene Mirro on Sun, 01/27/2013 - 18:57

Once the plants get a couple of true leaves, I take them out of the propagation domes and place them under the lights.  They toughen up in about a week.  Then I transplant them, and move them back under the domes for a week or two until they get established in their new pots.  Then they get moved out of the propagation domes again, and either under the lights or in the unheated greenhouse, depending on what time of year it is.  Losses with this method are almost nil, even with little prima donnas like fringed Gentian.

Submitted by Gene Mirro on Sun, 01/27/2013 - 21:10

From Chris:  "The relay contact rating in a Normally Open setup is 16 Amp @ 120 Volts, the load is 8 x 60 Watts: 480 Watts / 110 Volts = 4.3 Amps

Yet for some reason the relay contacts would occasionally get stuck in the closed position and not de-energize the system resulting in the system overheating several times. They replaced the unit free of charge, but even the replacement unit did the same thing."

Maybe the problem was inrush current.  When you first apply power to an incandescent lamp, the current is 9 - 15 times higher than the rated lamp current.  That can weld the contacts on a relay.

One way to fix it would be to divide your incandescent circuit into two parallel paths with half of the lamps in each one, controlled by two separate relay contacts.  Now the inrush current is half what it was before. 

Another way to fix it is to use an inrush current limiter. 
This has a high resistance when it's cold, and a low resistance when it's hot.  So it's just the opposite of the lamps.

Another way to fix it is to use a proportional temperature controller.  I really like this, but it's expensive.  It will vary the power to the lamps to keep the temperature constant, as measured by a thermistor or some other sensor.  This means that the lamps won't get turned completely on and off, which greatly reduces their life and causes inrush current.

Another thing that can burn relay contacts is arcing when the contacts open.  This usually only happens if you've got an inductive load.  This can usually be solved by using a surge suppression device, like a MOV:

It is to bad there is no continuation on this topic, looking at all the seed starting chronicles, it would be nice to see how everybody is germinating and root cuttings, what do you use, like lights, shelves, greenhouse, cold frame, etc.

I do a lot of seeding and cuttings under lights and in the greenhouse, and will get some pictures posted of my setup in the next few days.

I will try to add a picture as this is the first time adding a picture to a post.

Hi, Arie,

My setup is very much like yours - a wood-frame shelf system.  Looks like yours is much bigger though!  

The bases of the shelves on mine are sheets of anodized aluminum (not that it matters to anything).  A difference with my setup is that each shelf has two four-foot fluorescent light ballasts suspended over it on chains from the frame of the next shelf above; this allows the lights to be lowered down to sit directly on top of the plant trays, and to be raised as the plants grow.  

I'll try to add a picture, though it's not so terribly photogenic!  ;-)

Edit:  Here's one.

Looks like you have a lot growing!  It would be great to hear about your germination and growing efforts, either in this thread or in the Seed-Starting Chronicles thread.

Thanks for posting!

Submitted by Longma on Mon, 03/24/2014 - 05:08

In reply to by Lori S.

Very nice looking structures Arie and Lori. Obviously very successful ones too. What lights do you use?

I use T5's 3 in a row and 6 for each 8 ft of shelf. I will do a reading as per foot candles and post it later. I have enough room for 72 flats there are 2 rows of them.I also use it for growing some geraniums, ivy's, fuchias etc.for my summer planters outside

My grow room is in the basement, and is build out of 2X3 pine lumber. the shelves are 1/8 inch thick white recycled greenhouse polyethylene.

Lights are 54 watts high output sunblaster fixtures, purchased whole sale from a B.C. Canada company.

I have 3 lights in a row and 6 per shelf each shelve is 24" X 96" the lights give me about 500 foot candle at the plant height.

I do not have them adjustable, but my shelves are 17 " apart, and if I want more light I just put a couple of empty flats underneath the seedling trays.

I loop together 6 lights and I can have 24 lights on a 15 amp circuit, so enough for 4 shelves each shelve has its own receptacle.

Some one has to help me, as I can only post one picture per reply, so Lori please help me, as I took a lot of pictures from my grow room and greenhouse.

I have the capability to use heating mats, but found that I was getting enough heat from the lights below to maintain 68 -70 F at night and about 60 F during the day.

My lights are on for 16 hrs and because the nights are off peak rates I have the lights on at nights.

Submitted by Arie Vanspronsen on Mon, 03/24/2014 - 07:24

In reply to by Arie Vanspronsen

This is a picture of my timer, Intermatic 24 hr timer and beside the timer is a a thermostat , if I want to use a heating mat.

The timer is capable of about 15 amps so enough for one bank of 24 lights.

Hi, Arie,

When you hit "Reply" to this message, scroll down in the page to Embedded Images.  After you Choose File and then hit Upload and then Insert (to show your photo in the text box), you will see that another "Add new file"  box opens underneath the one you just used.  It works exactly the same as the first one.  So with each photo you add, another box opens in Embedded Images to let you add another photo.  I don't know what the limit in number of photos is.

Hope this explains it.