Standing tall and proud with their often bright yellow but sometimes with orange or white flowers, no plant shouts “Summer is Here!” like the iconic sunflower. Sunflowers make a great addition to the garden or allotment and will bloom right into the early autumn. They are also particularly easy to grow and are perfect for getting kids involved outdoors and off their video games. Sunflower seeds are also a tasty treat and as you know they have a hard little shell so you may be wondering “Should I soak sunflower seeds before planting?”.

Sunflower Seeds
Affiliate Disclosure

Should I Soak Sunflower Seeds Before Planting?

Sunflower seeds are known for their tough little exterior and anyone who has eaten them will know that they can be a pain to get into so just imagine how the young seedling is supposed to push through this outer shell. Many seeds with a tough exterior need a little helping hand to help them germinate and sunflowers are no different. Sunflower seeds will benefit from soaking as this softens up the hard outer shell enabling the plant to piece through on its way to becoming the great summer giant that we know and love.

Seed Soaking and Scarification – Garden Doctor

How to Soak Sunflower Seeds

Soaking seeds is an age-old trick and not a difficult thing to do at all and there are obvious benefits to giving your seedlings the best possible start in life. With a soaked, softer outer shell, the young plant embryo will find it far easier to begin life and start heading towards the light.

What You Need

  • Small Dish
  • Warm Water
  • Sunflower Seeds

1. Choose Your Seeds

First, you will need to choose your seeds.

Sunflower Seeds
Sunflower Seeds

There are over 70 varieties of sunflower so you will want to choose the right one. Sunflower varieties come in a range of colours and sizes with some dwarf varieties growing just a couple of feet and others growing nearly as tall as your house.

2. Prepare the Bed

When you have an idea of where you are planting your sunflower, you will want to prepare the bed.

Freshly Prepared Bed for Sunflower Seeds
Freshly Prepared Bed for Sunflower Seeds

Sunflowers will thrive even in some of the worst soil types and are drought-resistant with the most important ingredient being the Sun so ensure that you choose a sunny location!

3. Soaking

Take a small glass or dish and place your seeds inside and then cover them with water.

Soaked Sunflower Seeds in Water
Soaked Sunflower Seeds in Water

Some people prefer to use warm water although personally, I have never seen any difference between warm and cold. Leave the seeds in the water for around 8-10 hours before sowing.

4. Sowing

For best results and to ensure that you do not oversoak which can drown your seeds, we advise that you soak your seeds overnight and sow first thing in the morning.

Sowing Sunflower Seeds
Sowing Sunflower Seeds

Sow your seeds after the last frost directly into the garden as sunflowers do not like to be transplanted.

How to Sow Sunflowers Seeds

  • Find a nice sunny spot, for taller varieties preferably against a wall or fence for wind cover.
  • Sow sunflowers an inch deep directly in the soil (they do not like to be transplanted).
  • Sow 3 or 4 seeds every 6 inches to allow room for germination.
  • Water well.
  • Once seedlings reach 4 inches, you will need to thin them down to just 1 every 6 inches choosing the strongest-looking plant from each small group.
  • Water around once a week depending on the weather. (Do not water around the stem directly but water in the gaps between flowers – sunflowers do not like it too wet!)

How Long Does It Take for a Sunflower to Grow?

For a sunflower to reach its full potential and crop, sunflowers need to be in an area that gets at least 8 hours of full sun per day. Including harvest, there are 6 main stages to the life cycle of a sunflower which takes approximately 125 days.

1. Germination – 3 to 10 days

If you have soaked your seeds, you may see the sunflower shoot after as little as just a few days, but they can take up to 10 days before rearing their heads.  The first leaves to appear are the cotyledons and they are there to serve as the solar panels until the plant begins to grow its first set of true leaves.

2. Plant Development – 10 to 35 days

The development stage is an important time for your young sunflower. During this time, they require as much sunshine as they can get. After the cotyledons, the first set of true leaves will appear, and the plant will begin to grow extremely fast. Ensure not to overwater your young plant and make it drown.

3. Budding – 35 to 65 days

At this stage, your sunflower is starting to mature and grow enough to produce a bud. Seeing the bud is an extremely exciting time and means that so far, everything is going right. As the small sunflower opens, it faces and tracks the sun throughout the day in an incredible process called heliotropism.

4. Flowering – 65 to 85 days

Approximately 2 – 3 months after sowing, your sunflower will be in full bloom bringing a little sunshine into everyone’s day. This is when the bees and other pollinators will visit the sunflowers to drink the nectar and transfer pollen from one plant to another. At this stage, the heliotropism will stop and their stem will become firm and your sunflower will face the east.

5. Seeding – 85 to 105 days

By now, the sunflower will have been pollinated and during this time, the sunflower will be growing and producing its seeds ready for harvesting. This is when you will have to keep an eye on the birds that may fancy snacking on your sunflower seeds before you harvest and can eat them for yourself.

6. Harvest Time – 105 to 125 days

Now it is time to harvest the seeds. Seeds can be stored away to grow next year, or you can keep them for eating. Sunflower seeds make a great healthy snack and are especially nice when roasted. There is nothing more rewarding or tastier than eating something that you have nurtured and grown yourself.


Should I soak sunflower seeds before planting? Well, yes, it will certainly help wake up those little embryos and soften up the shells to give them an easier way out. Be careful not to overdo it, some harder seeds can be soaked for up to 24 hours, but we do not recommend that long for sunflower seeds, 8-10 hours will be more than enough.

Life-cycle of a Sunflower Infographic

Garden Doctor Tips

“For maximum fun with the kids, grow Sunzilla. Sunzilla sunflowers can grow to an amazing 16 feet tall!”

“Soak your seeds just before bed and sow them as soon as you wake up!”

“Ensure you buy raw seeds, roasted and salted seeds will not be viable!”

Sow in late spring for an awesome harvest at the beginning of autumn!”

“Do not over-fertilise your sunflowers, this can make them weak and not grow properly. A little slow-releasing fertiliser will be okay!”

Frequently Asked Questions

How do you soak sunflower seeds before planting?

Place your sunflower seeds in a small glass or dish and cover them with water. Leave the seeds for around 8 hours (best to do it overnight) and then plant them as soon as you wake.

Do sunflower seeds need to be soaked?

Sunflower seeds will benefit from being soaked overnight to soften their hard outer shell allowing the embryo to sprout through and grow into your sunflower.

How long does it take for a sunflower to grow?

It will take a sunflower around 65 – 85 days to grow enough to flower. After flowering, it can take another 40 days to grow and produce the seeds that we know and love. From planting to harvest, the lifespan of a sunflower is approximately 125 days.  


Trevor Wright is not just a seasoned horticulturist; he’s the esteemed Garden Doctor. With a BSc in Horticulture and years of hands-on experience in the soil, Trevor has become a trusted mentor for all things gardening. As the founder of Garden Doctor, he’s committed to clarifying the intricacies of gardening, offering straightforward advice that’s rooted in years of practice. His writing is a garden of how-tos, savvy insights, and comprehensive guides that enable individuals to nurture and grow their garden dreams. When he’s not knee-deep in garden beds, Trevor is at his keyboard passing on his green-thumbed wisdom to budding gardeners, ensuring that the legacy of sustainable and joyful gardening blossoms far and wide.

More You Might Like