Propagator info

Hi Guys,
I have a new good sized propagator arriving soon from UK but I know absolutely ZERO about working something like this

..... can somebody give me some ground rules so I can have some nice veg plants to go into my greenhouse at the right time and eventually a good veg season in my allotment
Many Thanks
Nick

 

Ciao Nick
The link below gives some good advice on using a heated propogator . My advice is , a themostatic prop will germinate the seeds at temperatures up to 25°c , a non thermostatic normally heats the seed tray to +3°c over the room temperature. When the seeds have germinated move them on to a room temperature of +15°c to progress. Now how sensitive to temperature vegetable seeds are to germinate, I dont know........... I am sure there are some gurus on the site who can advise on this.
http://www.thegardensuperstore.co.uk/sankey_plantmaster_2000_electric.htm

 

Harry - thats a useful link. As you say there is a big difference between ones with a thermostat and those without. I use one that doesn't have a thermostat, but it raises the temperature by about 5C. Inside the house, at this time of year, it works really well because the house is heated. But if I were to put it in an unheated greenhouse at -5C, the extra 5C would hardly keep it frost free, and it won't germinate much at that temperature. Ones with thermostats have bigger heaters, but I think they would still struggle in a greenhouse at the moment.

Varallo - I know nothing about veg, so can only speak in general terms. Different seeds need different conditions to germinate. However the majority germinate better with heat. The reason being that nature tells seeds not to germinate until spring is here. And the artificial heat of a propagator is one way of fooling seeds that spring has arrived.

Seeds can be germinated at any time of the year with a heated propagator. However, if you start them too early it won't be warm enough to put them outside.

 

Nick see this for info regarding optimum temperatures. It's very good.

http://tomclothier.hort.net/page11.html

and this (the main index to the above) for much more info

http://tomclothier.hort.net/index.html

 

My propagator suggests a layer of sand on the base ,about 1" I think it was , whats the thoughts on that. :cnfs:

 

DaveW , thanks for the links . really useful site showing and explaing the relationship between temperature and germination rate. I am going to read that in some detail later.:gnthb:

Pamsdish , the sand will act as a heat-sink which will hold the temperature in the sand and help to distribute it evenly over your prop and smooth out any temp' fluctuations. Now my prop is in the house , so I am sure Mrs H won't appreciate 1" of sand being spread over the kitchen :D.
Another useful tool when using a prop is a good gardeners thermometer , as you need to measure the compost temp' and not the air temp'.

 

Hi Guys,
Many MANY thanks.
HarryS,
PeterS,
DaveW
Pamsdish
Now it seems the idea of an amount of sand at the bottom is a nice and logical idea. So I will try that and then I will start a hunt ( unfortunately Italy is about 25 years behind UK in gardeing things !!!) for some John Innes compost for the seeds. Applying all the advice with the super propagator (which I got from the supplier (Greenhouse Sensation))
I gather from various spots I have looked on the net that once the seeds show the first proper leave I should take them out of the prop and transfer them to a cooler spot - which I have - and is in my shower room under the skylight. I gather this allows them to grow strong and with good light they should not become too leggy !!!
Please correct me folks if my strategy seems incorrect or if you have any other comments.
Fortunately there is still a good bit of time left to test and prepare as my greenhouse (unheated) will not be available temperaturewise until around March/april
Thanks again,
Nick

 

I've got about one and a half inches of sand in mine and as Harry S says it acts as a heat sink an it also helps maintain humidity if you water it. I know some folk rely on dry sand and just water the trays/pots but I keep the sand pretty wet which also helps reduce the amount of water I have to apply directly to the pots.

Nick - If you move your trays of newly emerged plants to your shower room with just a skylight directly above them they'll tend to be drawn up to the light and become leggy and weak. You'd be better if you could provide all round light.

 

I put my seedlings on the window ledge when I start them early in the Spring. The light is not perfect, so I make a reflector from an old box lined with tin-foil behind them which I have found makes a big difference. I think I have picture somewhere - if so I will post it here

 

I wouldn't use too much sand unless you have a thermostat and a hence a more powerful heater.

I bought a heated propagator without a thermostat some time ago, and then bought a seperate thermostat with a thermocouple sensor. I did some experiments - naively thinking that the entire contents of the propagator would all be at the same temperature - but it wasn't. By moving the thermocouple about I noticed that there was a big temperature gradient from the bottom to the top. At the bottom of the pots of compost the temperature was 15C above room temperature, in the middle of the pots it was 10C higher, but at the top of the pots where the seeds and first roots would be it was only 5C higher.

A moments thought told me that this was entirely logical. The heater was at the bottom, giving out a constant amount of heat. When the propagator was full of square pots, it was essentially full of compost - or sand - or any other material. Any material that you put in will be an insulator. And any insulator will stop heat escaping and consequently have a temperature gradient across it. If you put an inch of sand in the bottom, the seeds will be an inch further away from the heats source and consequently about 5C cooler.

If the propagator has a thermostat, the thermostat will also be at the bottom, and not registering the temperature where the seeds are, but you have the option of setting the thermostat 5C higher.

If you want to provide extra humidity, you can pour water straight onto the floor of the propagator. I do this with cuttings and find that it helps enormously.

 

Gratefully assimilating the various comments .... I have to mention that the propagator I have is the one sold by "Greenhouse sensation" double length (MT 1.20 and wide MT 0.60) and the heating is controlled by a thermostat that is inserted into the soil ...... I am assuming the heat is fairly well distributed but will no doubt find out in due course so my problem now is really whether or not and /or how I construct a neon light .... the type especially used for growing plants ... over the prop and how high over the prop. At this moment I plan to make a construction of three planks of wood in an inverted "U" shape attaching the neon light to the underside and reckoning to have the neon tube light (18W) about 45cms from the base of the prop.
I am tremendously grateful for all the comments especially as I find in visiting various gardencentres over here Nobody but NOBODY has even heard of a propagator so that rather reduces local advice !!!
Cheers,
Nick

 

Something happened when I typed Mts 0.60 ( meaning 60 cms) ...... Just to clarify

 

Varallo - just had a look at your propagator - looks good - rather larger than mine. Hopefully you will get a uniform temperature across the propagator, but it will always be warmer at the bottom closer to the heater than at the top - thats a general property of any system with a heater.

Have a look at this thread http://www.gardenerscorner.co.uk/forum/brugmansia-grown-in-pot-t30443.html At the bottom there is a picture of my own propagator with some fluorescent tubes above.

There are two main sorts of grow lights. It is generally acknowledged that for seedlings and cuttings (ie small things) fluorescent tubes are the best. They are the cheapest to run, as they only get slighty warm and consequently you can put the lights very close to the plants or even touching them. That way you make best use of the light, which falls off in strength the further away you go. That is the system that I have in the picture. Its a good idea to be able to lift or lower the lights as you want them as close as possible to the plants. Whilst yours will just about work with 18 watts of fluorescent tube, it would work a lot better with about 100 watts, which would give the sort of light level that you really need for plants to grow. Mine uses 90 watts (3 three feet tubes) over an area which is perhaps a little smaller than yours. I use a light meter which tells me its a good light level.

But fluorescent tubes are not so good for large plants. It is generally recognised that you need a metal halide bulb (or similar), which can be very bright (400 watts) and pretty small. This allows the light to be focused more like a searchligh and consequently get a high light level at the bottoms of plants as well. But it is more expensive to run as they run very hot and will normally need to be further away from the plants. There is some discussion on this thread http://www.gardenerscorner.co.uk/forum/grow-lights-t30165.html