why do my tomatoe plants get so tall?thank you.
Tall is a relative term. I presume your tomato is an indeterminate type, not a determinate type. Size is dependant upon genentics, but is also affected by things like shade, lots of water, and excessive nitrogen. When your tomatoes come up out of their cages of beyond your stakes, it is OK to prune them back a little. That will encourage blooms on some of the side shoots. It is almost always the case, however that tomatoes need support above the top of a 6' stake and over the top of even that tallest tomato cages. If you bought short cages (2 heights are common) you can drive a tall stake through the edge of them to give you some extra top support and to keep them from tipping over in a strong wind.