You will get much earlier tomatoes if you pot tomato seedlings up into larger pots before planting them in the ground. This page explains the how and whys of potting tomato seedlings up into pots.
There are big advantages is potting tomato seedlings up into larger pots before planting them out as larger seedlings/small plants instead of planting the seedlings directly into the ground when still small. These advantages are:-
- ABSORB HEAT MORE READILY
Being black the pots absorb heat, which warms the soil. The warmer the soil the quicker the plants will grow. Assuming the same air temperature and moisture conditions a plant in a 14cm pot will grow faster than one planted in the ground right next to it. - CAN BE KEPT IN THEIR POTS LONGER
Plants can be kept in their pots for up to four to six weeks before planting them out, whereas seedlings that have reached transplanting size in single cell seedling trays or seedling punnets can only be held for a week or two before they need to be planted out. - ARE PORTABLE
Pots can be kept in a greenhouse or a more sheltered spot before planting out when the weather is warmer and the risk of a late frost has passed. - PLANTS WILL BE BIGGER WHEN PLANTED OUT
In Ballarat (where I live) the traditional time to plant tomatoes is the start of November. By the time plants in pots are planted out they would have grown way beyond the seedling size and therefore will start producing ripe fruit earlier than seedlings planted out at the same time. - EASY TO STRESS A PLANT IN A POT
Stressing tomato plants in their early stage of growth will induce them to set early fruit. This is easier to do when the plants is in pots. For more information about stressing tomato plants to induce early fruiting see: Stressing Tomato Plants To Encourage Early Fruiting
The size of pots that are suitable for potting seedlings up into can vary, but keep in mind that the smaller the pot the shorter the time that the seedling can be held in that pot. But if the pot is too large then you will be using excessive amounts of valuable potting mix.
My preferred pot size for potting up tomato seedlings is 14cm, it is large enough the hold the plants in them for four to six weeks but small enough that they do not use large amounts of potting mix.
Tomato, eggplant and capsicum seedlings growing in single cell seedling trays. While these vegetables can be grown in punnets they will transplant more easily when grown in single cell seedling trays.
Tomato plants that have been potted up to 14cm pots. They can be held in these pots for four to six weeks before planting them out.
