Spring and summer, is always a good time, you can usually get another harvest in the fall if you have a greenhouse. Tomatoes love nitrogen, you have to give them chicken fertilizer, bat guano etc, and they are good organic fertilizers with a high nitrogen number.
If you find difficulties to grow tomatoes in pots, you may strive growing them in black plastic baskets.
Basket provide good drainage, good air ventilation, No over watering problems and lasting too.
If you can sprout your seeds indoors, you can grow them now. First of all you need to get a plastic cup. And then you should place 1/2 inch of potting soil in it,
Wet the soil with clean water. Lay your seeds on top and sprinkle
A few drops of water over them. Cover the seeds with a loose layer of dry soil.
Sprinkle water every day and you will see the young little plant is coming up.
Stake them with toothpick when they are one inch tall.
When the night temperature is up to 20°C or 68°F, this is often the most effective time
To move your plants into baskets and stake them with longer bamboo sticks.
Add two or more earth worms in the baskets; they will generate your instant fertilizers.
Their roots should be lined all the time and also the soil should always be wet.
Tomatoes love plenty of sunlight and water.
Prune off the side shoots which stay at 45° between the stem and the branch as soon as they appear.
They are known as "Suckers". This way the flower Clusters will soon growing into sweet tomatoes.
Top the plant when 3 to 4 clusters of flowers appeared. So that they will concentrate on growing the existing fruits. When there is heavy rain fall, a head shelter may help the plants to grow better.
I hope it helps!