and this is why ignore options were invented
As stated above breaking off the head as/after it goes to seed
is like harvesting "cut flowers" aaaauuha
the cattail is a root bulb plant, and the head is at the end of its yearly growth cycle . . .
For those that wish to stay the spread of seeds in a pond . . .
before breaking the head off put a bag over it.
The invasive part sounds funny to me . . .
What is a pond with out cattails . . .
It makes for a habitat for water fowl . . . and I have seen ponds/slews
that have never changed cattail density for 20 years +
It's been said that:
The cattail is more useful than a pig,
as everything pig is useful except the sqweeeeeeel . . .
And a cattail has no sqweel.