I have recently come across giant vegetable growing and didn't realise it was such a big event.

At my children's school, we have recently started a garden club and I thought a good way to get the kids interest was having a giant vegetable competition.

To make it simple for the kids we decided that we would stick with sunflowers, getting into larger vegies later.

I have been given several hundred seeds of Giant Russians by a very generous Aussie Gardenwebber. We plan on giving the kids a few seeds each (depends how many kids want to enter) to take home and grow over the summer holidays. Early next year, when the plants are ready we will measure the flower heads to see who has grown the biggest and they will win a prize.

What I would like to know is there any special tips on growing large sunflower heads? I'm not expecting record breakers but would like the kids to have fun and not be disappointed. I have grown normal size sunflowers and most of my own vegies so do understand basic growing techniques just need tips on getting bigger sizes.

Climate here gets quite hot over Christmas, average 30 to 35 Celsius (not sure in F about 90's?), can be dry but in a normal season, usually receive regular storms with an inch or two of rain at a time.

Any help you can give me would be greatly appreciated.
Thanks from Oz.

I thought just flower head size to start with as some of the kids are less than a metre tall as it is and as we are in a rural area many of the kids have to travel on the school bus. I can just imagine them carrying a sunflower a few metres long in the school bus :)