Author Topic: Propagator Lighting  (Read 282 times)

George the Pigman

  • Acre
  • ****
  • Posts: 321
  • Birmingham, neutral clay soil
Propagator Lighting
« on: December 06, 2017, 12:38:13 »
In a garden centre yesterday I saw a propagator with a light system above it. It seemed attractive as I have a greenhouse without a power supply and always suffer from leggy pants in early spring when they germinate. I thought maybe I could set it up in my garage.
Has anyone tried this sort of lighting. Does it work?

ed dibbles

  • Acre
  • ****
  • Posts: 479
  • somerset/dorset border. clay loam.
Re: Propagator Lighting
« Reply #1 on: December 06, 2017, 16:12:19 »
I use LED grow light panels to over winter some plants and prevent the very legginess you describe from early sowings, particularly tomatoes and peppers.

They are suspended over the plants with aluminium foil sheets around a frame to keep the light on the plants/seedlings.

They are low wattage so economical to use. One thing I have found is a far less incidence of seedlings damping off perhaps because the extra light boosts the seedlings. :happy7:

Beersmith

  • Half Acre
  • ***
  • Posts: 177
  • Duston, Northampton. Loam / sand.
Re: Propagator Lighting
« Reply #2 on: December 06, 2017, 16:38:06 »
Ed, thank you for the input.

I bought an LED grow light, with the same plan but have not gotten around to using it yet. I'll certainly be making use of it next spring.

Cheers
Not mad, just out to mulch!

ancellsfarmer

  • Hectare
  • *****
  • Posts: 801
  • Plot is London clay, rich in Mesozoic fossils
Re: Propagator Lighting
« Reply #3 on: December 07, 2017, 20:32:12 »
Use of a heated propagator should be limited to germination, ie sprouting. For most varieties ,light is not a pre-requisite (They are planted under compost)
Control of temperature is critical.
Once sprouted, they require growing conditions with correct, stable temperature, good light and (only just) sufficient  moisture. This is the problem stage, especially at certain times of year. Without electricity of some kind, the solar day will be insufficient. Battery sources with solar charging might help, with remote charging(take the battery to power!) if you can spare the time.
This years project is to build a mega sized growing frame (with grolux tubes) and fan ventilation to regulate temps. Will report in due course. The development work features in many prosecution reports!, but I don't grow pot plants.
Freelance cultivator qualified within the University of Life.

Vinlander

  • Hectare
  • *****
  • Posts: 1,346
  • North London - heavy but fertile clay
Re: Propagator Lighting
« Reply #4 on: December 11, 2017, 13:04:58 »
I agree with the above, but I'd say that the worst problem stage is when your seedlings need heat and light 99% of the time, but if the skies do miraculously clear in daytime there is already "heat in the sun" (say mid-February/March) - so your heated propagator suddenly heads for 40C and the plants get braised to death.

A thermostat isn't enough to stop this - and vents alone won't cope - you either have to lift the cover in the daytime, or place the whole thing somewhere there is bright light but no direct sunlight - and if this is in a greenhouse make sure the auto-vent is working or the whole greenhouse could become a slow cooker - it only takes one day to mean curtains (45C is actually used in slow cooking).

LED lighting is so efficient and cheap to run it is tempting to totally sidestep the problem and keep the whole propagator inside the house away from windows - even in a cupboard or under the stairs.

I would be doing this already if I had a cellar or SWMBO wasn't channelling Imelda Marcos. I'm seriously thinking about going under the floor - the attic is too busy.

In the cupboard or spare room you can do without the problematic and expensive heating - and when the LEDs come on (ideally for 18-20 hours a day) the little bit of extra waste heat will compensate for the boiler going off - especially if it uses a low-voltage PSU that you can place under the tray.

If your lights are mains GU10 ones like mine (currently 80p for 350 lumens from my local pound shop) and your attic or shed  is cold then put everything in a big enough cardboard box & keep all the heat inside.

And yes, watering is crucial, but a very simple raised-platform capillary system is the very best approach to keep the watering in the Goldilocks zone. Outflanking unpredictable temperatures means you can add water every one or two weeks - no need for a budgie-feeder reservoir.

Cheers.

PS. LEDs are so reliable it's pointless to use sockets for low voltage ones - it's better to wire them into a box permanently and avoid the risk of dodgy contacts in bulky (& expensive) sockets - and ideally improve resistance to humidity too. If you're qualified then you can do the same with mains ones.
With a microholding you always get too much or bugger-all. (I'm fed up calling it an allotment garden - it just encourages the tidy-police).

The simple/complex split is more & more important: Simple fertilisers Poor, complex ones Good. Simple (old) poisons predictable, others (new) the opposite.

Tee Gee

  • Hectare
  • *****
  • Posts: 6,022
  • Huddersfield - Light humus rich soil
    • The Gardener's Almanac
Re: Propagator Lighting
« Reply #5 on: December 11, 2017, 14:15:15 »
Quote
the worst problem stage is when your seedlings need heat and light 99% of the time

I agree!

OK I would love to have LED's but I have had my system for so long (teens of years) and I don't particularly want to go to the expense of changing my set up.

From the outset I have had three forms of heat, four if you include my cold frames, and what is being discussed here is my reason for having them.


Initially I use a a Propagator for 'germination' purposes, then once the seed has germinated I place my trays on to a hot bed in the open air of the greenhouse. If needs be I have cheap tray propagating lids which I use to cover the trays of seedlings to gradually accustom the seedlings to cooler temperatures.


Having said that I find that I only use the propagator when I want germinating heat of 60F (16C) usually with veg I just sit the trays on the hotbed with a propagator lid over them.

I keep the greenhouse at a maximum temperature of 40-45F (4-8C) for frost prevention ( It would be too expensive to heat the whole greenhouse for germinating purposes.)

Similarly I have an overhead "strip" light set up with a timer to supplement light above the seedlings if I deem it necessary.

Once I am satisfied that the seedlings are progressing quite nicely I put the trays on high level shelves where the get maximum light and as the greenhouse is set at 40-45F (4-8C) they are warm enough.

Then after a week or to the go out into my coldframes.

I hope this helps!



Here is a blog including pictures of my system showing what I mean!

http://www.thegardenersalmanac.co.uk/Data/Greenhouse%20heating/Greenhouse%20Heating.htm












Robert_Brenchley

  • Hectare
  • *****
  • Posts: 15,586
    • My blog
Re: Propagator Lighting
« Reply #6 on: December 16, 2017, 20:05:01 »
I don't have temperature control in the polytunnel (one disadvantage of the things; no automatic ventilation) and the spring temperature varies wildly from 40 degrees on a sunny March day to frost one night the end of last April.

Vinlander

  • Hectare
  • *****
  • Posts: 1,346
  • North London - heavy but fertile clay
Re: Propagator Lighting
« Reply #7 on: Yesterday at 12:24:24 »
I don't have temperature control in the polytunnel (one disadvantage of the things; no automatic ventilation) and the spring temperature varies wildly from 40 degrees on a sunny March day to frost one night the end of last April.

I agree that this is the #1 disadvantage of polytunnels - but it would be so easy to fix by clamping 2 full-length "stringers" in the roof say 40-50cm apart.

You could then split the cover & clamp it either side of the gap, leaving an opening that could be filled by splitting a single sheet of twinwall PC (so one sheet would do a 4m tunnel).  Putting a roof vent in (or an actuator on) the PC would be a piece of cake.

I'm definitely doing this when my current cover disintegrates (I never thought I'd regret buying the extra-inhibited type - it's brilliant) and in my case I would be able to buy a standard piece of poythene cover instead of wasting 70cm off a larger size like I do now. There are various refinements in a discussion in "Top Tips".

Cheers.
With a microholding you always get too much or bugger-all. (I'm fed up calling it an allotment garden - it just encourages the tidy-police).

The simple/complex split is more & more important: Simple fertilisers Poor, complex ones Good. Simple (old) poisons predictable, others (new) the opposite.

Allotments 4 All

Re: Propagator Lighting
« Reply #7 on: Yesterday at 12:24:24 »