I started some Russian Mammoth Sunflowers indoors at the end of January and they got quite stunted for various reasons. When I transplanted them in March they recovered quite well, or so I thought. Right now they're only 2.5 feet tall but have a completely opened flower about 5 inches in diameter. They don't have much foliage at all but the little they do have is a healthy green. They don't really look unhealthy, just more like a small sunflower. I've never grown sunflowers before so I have no idea what their progress should be. I'm assuming there is something wrong with these.

At the same time that I transplanted them in the middle of March, I also sowed some seeds and those are about 1 foot tall with big lush green leaves.

Basically, I'd like to know the general progress of a Mammoth sunflower and also what would have caused my transplants to bloom so small (other than being stunted indoors). How tall should they be after 30 days? 60 days? etc.

Thanks!