Load Stem

At what height do sunflower stems thicken?

I've planted a load of sunflowers and they are all about 12" heigh but the stems are all thin and the wind keeps blowing them over. Does anyone know or have experience of growing these and if so, what do they need to stand upright or how long does it take for the stems to thicken enough so they will stand up unaided by sticks, garden wire etc. I've even used pop bottles to prevent the slugs munching on them and to stop them falling over.

Well being from knasas, the sunflower state...that very much depends on variety. Wild varieties and ornamentals can grow viney and ten feet high, or hug dichs and alcoves. Commercial vareities for seed harvest grow 6-10 feet deppending on type and can vary in thickness greatly. If commercially produced seed, expect thickening as they approach thier mature hieght. Remember some commercial are no more than half an inch thick, and some can be up to two.

Enjoy vibriant collor it will give you.

---