[Superman]

They WILL need support. What support depends on your situation. If they are under, or nearly under, the eaves of your house, then you can put eyescrews and such in your eve, and run strings down and across, etc. You can then attach them to the strings.

Otherwise, some sort of freestanding setup will be necessary. If you have grown them a while indoors, repotted, grown them more, then put them in a huge hole with compost filler (always plant tomato plants DEEP. Those hairs on the stalks become additional roots, so peel the lower leaves off and always plant them a few, or several, inches deeper each time), then you will need a robust support system. If you didn't do all this, then a regular tomato cage is about all the bigger they will get.

Hooray for growing tomatoes! Grow Sweet Basil too. Basil can be the "secret ingredient" in nearly any dish.