Mystery growth

Mystery growth

What is this? http://www.fotolog.net/mscarolyn/ It appeared the day after I fed my lilly fish emulsion and it's grown this large, creating two other shoots in the process, over one week. Is it suffocating my lilly? It looks huge.
Dahlia pics

Dahlia pics

My room!

My room!

Does anyone else encourage “weeds?”

Does anyone else encourage “weeds?”

Plumerias; Shiitake Mushrooms

Plumerias; Shiitake Mushrooms

Strawberries

Strawberries

Dads Chrysanths

Dads Chrysanths