I am trying to grow Helianthus in my garden!  Have you ever grown them?
Yes I love them, I grow several types of sunflowers, I am an expert when it comes to them, anything you want to know about them? 
How long does it take for them to grow to full height?
Well I grow a special sunflower called "H. annuus", and it takes about 2 years if I'm not mistaken. 
Wow!  That is a long time!  can you eat their seeds?
oil sunflower seeds. The crops may be referred to as oilseed sunflower crops. These seeds are usually pressed to extract their oil. Striped sunflower seeds are primarily used for food; as a result, they may be called confectionery sunflower seeds.
The term "sunflower seed" is actually a misnomer when applied to the seed in its pericarp (hull). Botanically speaking, it is a cypsela. When dehulled, the edible remainder is called the sunflower kernel or heart.
Production.
In 2014, global production
decades. In a 2001 interview she stated: "My opinion is what it is... mine. Take it or leave it. Respect it or not. I will always have my own opinions and I am never be afraid to voice them. I don't want to revolutionize anything but myself. The more I learn, the more I change and the more I grow. I would rather be responsible for helping to open doors for women rather than closing them".
Furthermore, of the song "Beauty Fiend"