Planting Sunflower Seeds: 13 Important Answers You Need to Know

Planting sunflowers from seed isn’t as hard as you might think.

In this post, you will learn everything about planting sunflowers, for example how far apart you should plant them, how many seeds you should put in one hole, or reasons why they might not sprout.

1. Can You Grow Sunflowers From Sunflower Seeds?

Yes, you can grow sunflowers from seeds. It’s pretty common to plant sunflowers seeds that you eat. However, you should remember to plant only raw sunflower seeds.

Growing a sunflower from seed isn’t hard and it doesn’t demand any complicated skills.

Keep in mind that it’s possible to only grow a raw sunflower seed-the one that you can extract from a sunflower’s head or that you can buy in the store.

Salted or roasted sunflowers that you eat as a snack don’t have a chance to grow.

2. How Long Does it Take for Sunflowers to Grow From Seeds?

It takes from 3 to 4 months to fully grow a sunflower from seed. Fast-growing sunflower varieties take about 80 days to grow, and slow-growing ones up to 120 days.

The variety of a sunflower plays a huge role in how fast your flower will grow, but it’s not the only factor. Other important growth factors are:

  • Soil acidity
  • Temperature
  • Watering frequency
  • Access to sunlight

Sunflowers prefer soil that is slightly acidic to somewhat alkaline (pH 6.0 to 7.5). That means they can grow almost anywhere. However, if your soil is very poor, you can apply a slow-release granular fertilizer, like this one from Amazon.

Sunflowers grow better in temperatures between 70 and 78 degrees Fahrenheit (21-25 °C). Lower or higher temperatures aren’t harmful to them, but these are the perfect conditions for them.

Of course, you should also water your sunflowers frequently. Water them 2-3 times a week to keep the soil wet, but not let them sit in the puddle. You can read everything about watering your sunflowers, for example, what time of the day you should water them, in this article.

And probably the most important thing, which is sunlight. Always make sure that your sunflowers get 6-8 hours of direct sunlight daily. It grows best in such conditions.

3. How Do You Prepare Sunflower Seeds for Planting?

A raw sunflower seed doesn’t need any preparation before planting. However, if you collect sunflower seeds in the fall, and you want to prepare them to sow in the next season, you should know how to do it.

  1. Collect mature seeds
  2. Dry the seeds
  3. Rinse the seeds and let them dry overnight
  4. Put the seeds in the envelope and store them in the refrigerator

If you collect seeds, make sure they’re fully mature. In order to do it, cover the sunflower head that grows in your yard with a paper bag, and tie it close with a string to protect it from birds.

Keep the bag until the back of the flower head turns completely dark brown and the flower looks as if it’s dead or dying.

When the flower is dead, cut its stalk below the top of the bag. Turn it upside down and hang it from the stem in a well-ventilated spot in a warm, dry room until the flower head is completely dry. This can take from one to five days.

Shake bagged sunflower head every day to drop seeds that are ready. If they are dry, and falling off easily, they’re ready for storage.

Rinse the seeds thoroughly with cool running water. Allow them to drain freely for 10 or 15 minutes.

After rinsing, place the seeds on the newspaper, or towel. Leave plenty of space between them to allow for good air circulation. Allow them to dry at room temperature overnight.

Pick out plant material or debris. Sort through the sunflower seeds and pick out the plumpest ones, which are the most likely to be viable. Keep them separate from the rest of the batch.

Put the best sunflower seeds in a paper envelope. Then seal the envelope in an airtight plastic container and store it in the vegetable drawer in your refrigerator until you’re ready to plant.

4. Should You Soak Sunflower Seeds Before Planting?

Soaking sunflower seeds before planting isn’t necessary, but it can be helpful. It lets the seed soften up the hard outer shell, making the plant grow a bit faster in the ground.

Soaking seeds is easy. Here’s a step-by-step instruction on how to do this.

  1. Place your seeds in the glass.
  2. Fill the glass with cold or lukewarm water.
  3. Leave the seeds in the water for around 8-10 hours before sowing.
  4. Sow the seeds right after you bring them out from the glass.

From my own experience, I know that soaking seeds fasten the process of germinating a sunflower by 1-2 days.

5. Can Sunflower Seeds Be Planted Anywhere?

Before you plant a sunflower seed, you have to choose the right location.

Sunflowers need to be planted in a place where they will get 6-8 hours of sunlight per day, ideally where the soil acidity level is 6.0-7.5.

So, choose the sunniest place in your yard where no other plants will cast a shadow on your sunflower. Otherwise, your sunflower will experience stunted growth and can eventually die.

If you’re detail-oriented, you can inspect the pH level of soil, like this one from Amazon. It will also be helpful when planting other plants. The pH level should be 6.0 to 7.5, but sunflowers will grow basically on most soil acidity levels.

Also, don’t plant your sunflower seeds near potatoes, as sunflowers have a high allelopathic potential and may reduce the yield of present/future potato crops.

6. How Deep to Plant Sunflower Seeds?

It’s recommended to plant a sunflower seed an inch (2.5 cm) deep in the ground. If you plant the seed too deep, it might experience limited or failed germination and weak seedlings.

When it comes to sunflower seeds, it’s better to plant them too shallow than too deep.

So, to plant a sunflower dig a 1-inch (2.5 cm) deep hole with your finger, and just put inside your seed. Then cover it with the ground.

7. How Many Sunflower Seeds Do You Plant in One Hole?

If you plant outdoor sunflowers, you need to plant one seed in one hole. It will let them germinate smoothly without any disturbance.

If you happen to put more than one sunflower seed in the hole, then if more than one germinates, snip off extras at the soil line also. This prevents disturbance of the seedling roots on the one you’ll continue growing out when thinning. 

If you plant seeds in pots, this rule doesn’t apply. If you want to know how to plant and grow potted sunflowers, go to this post.

8. How Far Apart Should You Plan Sunflower Seeds?

The distance between two sunflowers seeds depends on the variety of a sunflower. If you grow tall sunflowers with branches, it’s safe to plant them 3 feet (1 meter) apart. If you plant dwarf sunflowers, plant the seeds 12 inches (30 cm) apart in all directions.

The sunflower plant needs plenty of room in the yard for proper root development and for the full development of the heads.

If sunflowers are planted too close, some plants might not get enough sunlight, and the root and heads might not develop properly.

If you crowd seeds, the plants will cast shade on their neighbors as they grow. Also, if the roots touch each other, it might affect the growth of both plants.

As a rule of thumb, it’s better to plant sunflower seeds too far, than too close to each other.

9. Can You Plant Sunflower Seeds Directly in the Ground?

Sunflower seeds can be planted directly in the ground. Just dig a hole that’s 1 inch (2.5 cm) deep, and cover it with soil. You should also remove grass, weeds, and pebbles to ensure the healthy growth of a sunflower.

Pebbles, weeds, grass, and other debris might stunt the growth of a sunflower, so whenever you plant the seed, make sure the soil is clear.

10. Do You Plant Sunflower Seeds Point Up or Down?

It’s recommended to plant sunflower seeds point down. The narrow end of the seed will emerge root, so putting this end down saves the plant from having to right itself in the ground.

By planting sunflower seeds point down, you give the sunflowers the best possible start in life, and you can speed up the germination process by another 1-2 days.

11. Should You Water Sunflower Seeds After Planting?

After planting, you should water your sunflower seeds deeply. You shouldn’t let them sit in the puddle, but the soil should be wet. Do it once or twice a day until the germination occurs.

Watering seeds when they’re under the ground is important because constant moisture let them grow properly.

Water your newly planted seeds light with a watering can if you don’t want to wash away the seeds or rot them.

12. How Many Days Does it Take Sunflower Seeds to Germinate?

Sunflowers usually germinate 7 to 14 days after planting. The germination time depends on many factors, like soil temperature, watering frequency, or how deep they’re planted.

If you do everything right, your sunflowers might pop up even in 7 days. However, they need to have an ideal soil temperature, preferably between 55 and 60 degrees Fahrenheit (12-15 °C).

You should also keep the seeds wet by watering them once or twice a day. And if they’re planted well-not too deep, 1 inch (2.5 cm) down, you can expect quick germination.

13. Why Won’t Your Sunflower Seeds Sprout?

There are a few reasons why your sunflower seeds aren’t sprouting.

  1. The wrong amount of water
  2. Inadequate temperature
  3. Incorrect planting depth
  4. Improper storage
  5. Unwelcome wildlife

With too little water, seeds remain dormant. With too much water, seeds become susceptible to rot. Seeds need to be watered deeply, without overwatering.

Sunflowers might not sprout because of the too low temperature. As a general rule, aim for temperatures above 50 degrees Fahrenheit (10 Â°C).

If your seeds aren’t sprouting, it might be because they’re dug too deep. If you’ve already planted and believe you mismeasured, simply try again with new seeds. The correct planting depth, which is 1 inch (2,5 cm), will make a big difference.

If you didn’t store your sunflower seeds correctly, they might be poor-quality or too old. If you plant your sunflowers from the packet, make sure to read how to store them. If you plant from the seeds from a sunflower’s head, scroll up to the third headline of this article.

The last reason that you can’t see the sprouts might be animals. Squirrels, rabbits, and other animals love to eat seeds. Next time, think about creating some physical barrier to avoid animals burying your seeds.