In case you are new to vegetable growing, I feel I should point out that tomatoes need heat throughout their lifecycle, both to germinate and grow healthy seedlings and to produce ripe fruit. Growers with sheltered, southerly gardens in Ireland and the UK should be able to grow tomatoes outdoors but for those of us in cooler latitudes, they are a greenhouse or polytunnel crop.
One of the tricky things about growing tomatoes is that, because they need as a long period of sunshine as possible, we need to start them off early in the year when conditions are less than ideal. Tomatoes need a soil (or more likely, compost) temperature of around 20˚C for the seeds to germinate so they will need to be sown in a centrally heated room (in pots or trays rather than directly into the carpet) or using a propagator or other heat source if sowing in an unheated greenhouse or polytunnel.
The difficult part is that, while we can easily supply the heat to germinate seeds and protect young plants from cold, it is more difficult to provide enough light to prevent them getting ‘leggy’ (tall and gangly with more stem than leaf). The earlier you sow, the more pronounced this problem will be because daylight hours and light intensity are low in February which is why, despite the advice on seed packs, I find it better to sow tomatoes from early to mid March.
It is best to sow in pots or trays in a greenhouse or polytunnel to benefit from as much available light as possible but if sowing in your house is the only option, find the sunniest, south facing window that you can. It is also worth remembering that, although tomatoes need around 20˚C to germinate, the resulting seedlings will do better grown at a lower temperature of around 14˚C when light levels are low as the warmer it is, the leggier they will get (if there isn’t enough light). If you have the option you can put plants in a bright but cooler place e.g. a porch or unheated room.
I think I mentioned this before but a plant growing indoors in a window will only receive about a third of the light available in an unshaded greenhouse or polytunnel. This is simply because the sun arcs across the sky so the sun will be behind your house for a significant part of the day. If you are growing on a windowsill with light only coming from one direction (a point on the compass, not the boy band), you can help things along by placing a foil backing behind your seedlings to reflect light back on the shaded side.
As you will see in a minute, tomato plants respond particularly well to deep planting (because new roots grow from buried stems) so house grown plants which have inevitably grown a bit lanky can be easily recovered, all I’m saying here is to give them as much light as you possibly can in your circumstances.
source : – Quick Crop