Planting, transplanting and supports
When seedlings are about 8 weeks old, it's time to transplant them to their permanent growing location. The right time, depth, and supports determine the future harvest.
Planting time
Before transplanting, tomatoes need to be hardened off – first, keep them in the shade outdoors for a few hours, then gradually accustom them to the sun, leaving them for longer periods.
Transplanting from pots should occur after the danger of frost has passed – approximately two weeks after the last predicted frost. Greenhouses are a few degrees warmer. It's useful to get a minimum and maximum temperature thermometer.
Soil temperature is also important: if it's below 10 °C, tomatoes won't grow. Tomatoes set fruit best at temperatures of 18–26 °C – it's worth trying to ensure flowering occurs before the peak of summer heat.
Transplant on a cloudy day or after the day's heat – until the seedlings adapt, the sun can easily burn them.
Source: pomidorai.eu