Where are you. I plant seed on April 10 and get tomatoes around late July or Early August. You can start them on Christmas but you won't get them much sooner unless you have a lighted heated greenhouse. They need warm temperatures and so many hours of daylight each day. If you plant early they will just sit there waiting for right conditions.
For tomatoes, you first need flowers and right now (UK) I'd suggest they will only just be budding. My strawberries, outside and not in a greenhouse, are just beginning to flower. I'd suggest your toms. may be the same. Unless you have them in a greenhouse when they'd be helped.
they like warm and lots of light. if it is not warm enough the majority of plants will stop growing
i planted tomatoes in February and it sprouted but then it stop.until now i see no tomatoes
