Should you compost your tomato plants?

Yes, compost everything -- you want to return all possible nutrients to your soil.  No, composting tomatoes spreads disease and weeds.

I'm ambivalent.  One the one hand, I don't usually have much trouble with diseased tomato plants.  I struggle mightily with insects, but haven't had much tomato blight or viral problems.  On the other hand, the old vines take forever to break down in my compost pile.  And I know for a fact that my compost doesn't get hot enough.

If I were trying to grow tomatoes from seeds, I'd never have any success.  But they are always popping up in the compost, after I've diligently spread it all around my garden.  Picture those huge, sprawling cherry tomato plants all over the garden!

Experts say you can safely compost tomato plants, even diseased ones, if you're confident that your compost pile reaches temperatures of 150 degrees, and you cure it long enough for all the plant material to completely die.  The worst of the tomato diseases, like late blight, cannot survive without a living host.  So in theory, if your compost-making process is perfect, disease won't be a problem.

If, like me, you don't have disease problems, go ahead and compost your old tomato plants.  My seedlings are as likely to come from kitchen waste as they are from garden debris.

Here's a good explanation of the tomato-composting issue.