"Blade grassy plant" isn't much to go on. Echinodorus tenellus, maybe?

In general though, with plants that self-propagate by adventitious plants on
shoots, or peduncles, you want to leave the baby plant attached until it has
at least six leaves of it's own and some fairly well developed roots. If
you can, bend the shoot over and anchor the new plant root-side down against
the gravel or sand with a small rock or some-such. It will develop more
quickly and then you can just cut it free.

kush

"You can't have everything - where would you put it?"

M Walczak wrote in message
news
I have a question about this blade grassy plant i have in my tank, it has
grown a shoot with a new little plant, would it be wise to leave or cut
it
and let it float near the top of the water until it grow bigger