I know it is winter but...

Depending on what they are, I wouldn't advise sowing before end January, even indoors - unless you have a room with something like a velux window in the roof, or a conservatory, they always get etiolated (leggy) because there's not enough light for them, and then, because they're indoors, they'd need hardening off before placing outside permanently, and with the winter we're having, you could end up having to keep them inside until March/April. Sown outside in February, they germinate when conditions are right.

Interesting idea I have got an aero garden and I have just bought a seed tray for it with the same thoughts the light and temperature will not be a problem at the moment I have a tomato plant growing about 12/15 inch high and the seed was planted about 4/5 weeks ago I also recently planted some Bomarea "Fiesta" seeds this will germinate around spring time after going through a stratification period also the same will be with some Lapageria rosea that I have got as well.

O.K, thanks for the advice.