How To Grow Sunflowers From Seeds Inside. This is how i grow sunflowers in my cutting patch, sowing the seed straight in the ground. The best time to plant sunflower seeds is in spring, although in many parts of australia, they will grow year round.
Be very careful in handling the seedling if you start them indoors. Cut the head off the plant leaving about 6 inches of stem. As the seedlings grow, thin the plants out so they’re around 45cm (18 inches) apart.
Alternatively, seeds can be planted outside directly once the risk of frost has passed.
If needed, top the pots off with a little more soil. The best time to plant sunflower seeds is in spring, although in many parts of australia, they will grow year round. My favourites are ‘red sun’ with velvet flowers in the deepest crimson and ‘valentine’ in a lovely pale lemon yellow. If starting your sunflowers from seeds, there are a few tricks you can use to get the best results.