How To Grow Sunflowers

by | Nov 9, 2021 | Gardening, Grow Your Own, Tips | 1 comment

Sunflowers are guaranteed to brighten up any backyard. Their bright yellow blooms are irresistible, inducing smiles in anyone that sees them. You don’t need to drive past a sunflower field to appreciate their beauty either. It’s easy to grow your own in your garden, giving you gorgeous giant flowers year after year.


Evident in their name, sunflowers (Helianthus) need plenty of sunlight to grow well. A minimum of 6 hours is necessary, but around 8 hours of unfiltered direct light is ideal. Before planting, amend your soil with compost and a dose of slow-release fertilizer like Atlantic Bio-Ocean – sunflowers are considered heavy feeders.

You may be surprised to find how large these plants actually grow (or, if the blooms are anything to go by, you’ve likely already guessed). The long taproot burrows deep in the soil to support the massive stems. When planting, loosen the soil quite far down to facilitate this growth. When growing in containers, choose a smaller sunflower variety and ensure the pot is deep enough to accommodate root growth.

Seeds can be planted throughout spring and summer once the soil is warm enough to trigger germination. Space seeds around 15cm apart and push gently into the soil. Smaller sunflowers can be spaced closer together, while incredibly tall ones will need a bit more growing room. Water thoroughly immediately after planting to stimulate growth.

To stop your plants flowering at the same time – leaving you with a pile of sunflowers and no clue what to do with them all – plant a batch of seeds every 2 weeks for about 2 months for continuous flowers. Flowers should shoot up within 2 months of planting.

The seeds should germinate in 7-10 days. Keep an eye out for pesky birds in the meantime that love snacking on sunflower seeds just as much as we do.


Sunflowers are not fussy plants, but will reward you with many more impressive blooms under the right care.

Due to their height, sunflowers will benefit from staking, especially in windy regions. Place stakes early to avoid disturbing the roots later on, and continue to tie the stem to the stake with a flexible material as it grows to stop the plant from falling over.

These plants grow best when given consistent water, though they prefer when the soil does not stay moist for too long. Once the top layer of soil has dried out completely, it’s time to water again. If the heads and stems and falling over, they’re telling you they need more water.

The slow-release fertilizer applied during planting should be enough to sustain your sunflowers. If you’re not seeing many blooms, apply a dose of fertilizer high in phosphorus and potassium to improve flowering.

You won’t encounter too many issues with pests and diseases when growing sunflowers, bar the light sprinkling of powdery mildew that is easily removed. Where you will have a problem however, is with the birds in your garden.

Birds are wonderful garden friends, and gardeners usually go by the mantra ‘the more the merrier’. However, they are sunflower-obsessed and will do anything to get to your sunflower seeds. Adopt a quick cut-flower approach by removing blooms as soon as they are ready, or install a protective barrier around your sunflower patch.

Sunflowers provide you with two benefits – stunning flowers and tasty seeds. Cut blooms in the early morning before the heat of the day sets in. They will need a tall vase and plenty of water to keep them standing upright. To harvest the seeds, leave the flowers on the stems until the petals have died back. Once the heads have turned brown, the seeds should be easy to shake off. Give them a rinse and eat them as a snack or toss a few into your favourite salad.