Hi all,

It's getting cold in Switzerland so finally got round to setting up something decent for thr winter. I have a Rootit medium mat, with 300W Dual spectrum (Blue 6400k & Red 2700K) CFL grow light & reflector as below.

I didn't expect the heat mat to put out such heat but after 24 hours (no lights, just heat mat), the soil was up to roughly 88F. Some of the leaves had fallen off since yesterday, so I'm guessing the roots are too warm. I will gradually move them outwards so that the pots are less and less on the heat mat until I see the roots roughly 80F.

Tonight I've erected the light and hung as you can see roughly 6 inch to 1 foot away. Unfortunately not all of my plants are the same size so it's not so accommodating for the big fella.

Got a lovely selection:

Lemon 4 seasons
Lemon Meyer
Orange Satsuma
Orange Caldoman
Orange Navel
Lime Tahiti
Lime Kaffir

I plan on putting some reflective survival material below the heat mat, also on both sides and maybe on the back wall too, to reflect as much light as possible. Also plan to pot the plants up once they've settled a bit into the usual orchid/citrus mix.

A few questions: what temp should I aim to keep the roots with a 300W light. Is the light close/far enough. Any other help/tips?

Couldn't fit the table next to the window as there was nowhere to hang the light, we move upstairs next month so I will put the table next to the south window also.

Pics:
http://upmyphoto.com/image/74727/a859673
http://upmyphoto.com/image/74726/e04a776
http://upmyphoto.com/image/74725/632fe04

Cheers

looks nice, very similar to my setup except I have my reflector hanging from the ceiling from a yo yo hanger. As for the seed mat being to hot I solved that problem with a thermostat like this:
http://www.sunflowersupplies.com/products/SUPER-SPROUTER-SEEDLING-HEAT-MAT-THERMOSTAT.html

you just plug the mat into the thermostat and a probe goes into the soil so it shuts the soil off at that temp. I keep mine at 70F which is the lowest setting and it goes up to 100F

The thermostat is a good idea, but I have different sizes of pots therefore I would have thought different soil temperatures......

There are three growth factors that influence root development. Water, temperature, and soil aeration. It has been found through experimentation by Girton that the optimum temperature for the growth of orange and grapefruit roots is 79F (26C). - Millet (468-)

Thanks Millet, maybe I'll get a timer and tinkle with the on/off times. Maybe 30 minutes on and 30 off may keep the roots closer to 80F. Or maybe bigger pots would do the trick......

How does the light setup look?

Indeed

Actually, I took some more readings. It was 85F at the bottom, 80F in the middle and high 70's at the top. I guess it's OK, having 80 throughout the pot is impossible with a heat mat! maybe with Christmas lights.....

So after a couple of weeks most of the plants are looking great, the lime and the meyer are showing loads of new growth. However the calamondin is looking droopy. Any reason why this type of citrus would not like a warm bed and 300W sun as his new home?