Question
I have been told to "top off" my plants on most of the limbs just above the blooms.  Is this what I should do?  I have been reading some things on line.  Thanks for your help.

Answer
Topping off will really depend on what type of tomato plants and how you want them to behave.

If you have a determinate tomato plant, topping off will probably not do much good.  Determinate plants tend to grow to a certain size and produce all the flowers and fruit at relatively the same time.  They do not continue to set additional flowers and fruit.  Often these plants are smaller and have a bush like habit.  These are the tomatoes that are usually used for commercial production.

Home gardeners usually plant indeterminate tomato plants.  These plants will continue to flower and set fruit throughout the growing season.  These plants can get quite large.  Some people will cut back or top their tomato plants to keep the plants more compact. This will often stimulate the plants to become more bushy, but they will not be as tall and leggy.  

Some people will top off plants as a way of getting larger fruits.  They will also have to remove blossoms and fruits that develop on side shoots.  This will make the plants put all of the energy into producing fewer, but often larger fruits.  If you desire large fruits, you may want to do this.  

I hope this information helps.  If you are not sure if your plants are determinate or indeterminate, it probably gives that information on the seed packet or plant label.  You can also search for the name of the variety on the internet to find the information.  If you have several plants, you may want to experiment and top a few just to see for yourself what happens.  Good luck with your plants!