Yeah, my volunteer tomatoes look almost as good as the carefully selected, propagated and pampered ones. I try to use it as a example of how I should let go of attempting to control nature and just go look at the zinnias, instead. Sunflowers are great as chop 'n drop mulch, the stems compost relatively quickly, the old ones are full of brownish white pulp that decomposers (grubs, ants, etc.) seem to love. Outer fibrous shells are very tough, will last a while and act as shade and surface moisture conserver. Just chop 'em where they stand or pull them up and lay the whole thing down on the spot. Roots are shallow, no tap root.