So what is the trick to getting them to grow so big? I know spot them in other gardens or have them spotted in yours the first hour after the flower. How do people get them so big though? I try and try but it doesn't happen for me.

I know when I grow any plant like the sunflowers, I open lots of tabs of gardens hosting the wildlife needed by visiting a fan group sprinkling list. With a hundred or so gardens open on different tabs, I can click through them quickly, water gardens that are attracting what I want & look due, and close gardens that aren't hosting or due.

What is a fan group sprinkling list? How do I do this?

There are several fan groups listed at the bottom of the Help page. Those links will take you to their website (outside FL) and you will have to navigate to find their sprinkling lists.

I'm personally a member of Freedom Fairies (FFU) and here's a link to their sprinkling lists. http://www.freedomfairies.com/sprinkling-lists.html

My computer can't cope with a hundred or so gardens open at the same time.   So I save gardens (either advertised gardens, or "no rules" ones from the fan site sprinkling lists) in folders on my computer, ten per folder (it's all my PC can manage!).  Before I start I open up the first folder in separate tabs, close down any which aren't due and leave the others open.  I'll do that with the first couple of folders until I've got about a dozen open then I'll dust up the plant and go quickly through the gardens I've got open.  If nothing is on the  plate I'll either close the garden down, or if the plate is over 4 - 4.5 hours since the last feed I'll leave it open.  I then open up each of the folders in turn and do the same thing, plus I'll revisit the ones I have left open every few minutes, and close them down once the wildlife is spotted so that I'm not holding too many open at a time.

Once I run out of folders, I'll either use the FFU list or the Wildlife Guide, opening ten at a time and working through them.  Part way through the time I'll go back through my folders again, as by that time more of them will be due.

It also helps if your own feeding tables are due.  I'll usually put out fresh food about half an hour before I'm ready to hunt, then once those first feeds have gone I'll dump the food and put fresh out again - often I can get a second lot to count towards the sunflower.

Thanks! I'll see if I can figure this out!