First, you need to get hold of some sunflowers seeds. April and May is the best time to start to grow sunflowers. You can easily find seeds in garden centres at this time, or sometimes supermarkets and hardware shops (my local ironmongers has loads of cheap seeds that are easy to grow!) If you know someone who has previously grown sunflowers, you could ask them if they have any spare seeds from the previous year.
To help the seeds germinate, place them in some damp kitchen roll and place on a warm window-sill for a couple of days. This isn't essential but might just help them get started before putting them into the soil.
You can then sow your seeds straight into the ground, or you might like to start them off in some small containers such as yoghurt pots or tin cans. All you need is some fresh soil or compost and a trowel or spoon to dig the soil. Place the seeds in about 1cm down and cover them over. Make sure you give them a good initial watering.
As the seeds start to grow you might want to thin them out (move then a bit further away from each other) to give them maximum space and light to grow. Slugs and snails love to eat the new shoots so you can protect them by cutting the top off an old plastic drinks bottle and place it over your new shoots.
As your sunflower gets taller, support it with a cane or secure it to a nearby fence so it can reach even higher. If you like, you can feed it with tomato feed which you can buy from a garden centre.
Finally, once your sunflower has bloomed and faded, harvest the seeds for next year so you can grow more sunflowers without having to buy more seeds 🌻