Uberpropagator

[Conrad]

I thought some may be interested to see my new arrangement for seedling starting, I call it the uberpropagator! Its not beautiful but is hidden in the spare room.

Made from 12mm ply, x3 levels each with x4 36w t8 flourescent tubes. The residual heat keeps seeds generally between 25 and 32 at the moment, so I will need to add a couple of little extractor fans to keep things cool once the weather warms up. Each drawer comes out all the way to inspect seedlings. These days I find regularly picking out any fungused seedlings and spraying with chinosol is worth doing so need access to them all. Working well so far and better than the spreading mess that preceded it.

[Pattock]

Timers or on for 24 hours?

[edds]

Great set up Conrad! That looks amazing. Now where do you grow them all on? I've got to build a new greenhouse for what I grow on a single small propagator!!!

[Conrad]

Thanks guys, the lights are generally on about an 16:8 day night cycle.

Everything us eventually moved into the polytunnel, I have a 16 x 36ft and have just put up a 16 x 48ft one too. Both with gas heating.

[fero]

Really like that, I've plans to build one similar one-day. Would you consider installing a fan to even out temps.
Happy growing

[Conrad]

Hi Fero, thanks, I can recommend it, really packs the seedlings in. Yes I will put a 120mm fan in on each level toward the back, I wired them up to a mains 12v adapter this evening and will cut some holes and fix them in place over the next couple of weeks, no hurry now as its a bit chilly outside!

[Pattock]

Are you planning on the fans pushing air in or pulling air out?

[Conrad]

I'll have the fans pilling air out of the back of the box, which is the warmest bit, the idea being there should then be a passive flow of cooler air in through the front.

[Pattock]

I'll have the fans pilling air out of the back of the box, which is the warmest bit, the idea being there should then be a passive flow of cooler air in through the front.

Personally, I would have them pushing in. Is there a fourth wall not shown in the photo? The turbulence when the air flow hits the front wall will help mix up the air more effectively before it is then forced out of the openings.

If you don't have a fourth wall, the air will just be dragged in from the centre and the corners will still get hot. In that case I would put the fans at the narrow end and have them blowing across the length of the shelf.

I have a filter before my fans to slow down the dust. They still need the blades washing once a year to restore efficiency but it is not as bad. I use the stainless steel spare filters from cafetières. A piece of loosely-woven cloth is just as good. They filter just needs to be brushed down every now and then.

[ralphrmartin]

A few comments, not aimed at the original poster, but just general observations:

(1) Many people seem obsessed with using artificial lighting. I just use daylight for my propagator (although I dont stack shelves), and my seedlings do just fine. Why use extra energy and equipment when sunlight will do a perfectly good job?

(2) Fans also seem pretty much unnecessary. I don't use them, and keep the humidity up. I've measured the temperature at over 63 C (!!) inside my propagator, and the seedlings carried on just fine (well, they survived, even if it wasn't optimal).

(3) I have a soil heating cable, and after reading Terry Smale's advice about how succulent CAM metabolism is geared up to lower nighttime temperatures, it is now on a timeswitch so it is off at night. While purely subjective, it does seem my seedlings grow quicker than when having the heating cable on 24 hours a day. It's also cheaper (apart from the cost of the timeswitch, < £10).