Best Time To Plant Sunflowers [Beginner’s Guide]

Last updated: 10/30/21

The sunflower is a plant that is easy to grow, very versatile, and makes touching, caring for, and sometimes planting the seed all real simple. Many people plant sunflowers in their yard because they are easy to grow, easy to look after, and easy to harvest.

But, if you are new to vegetable gardening, don’t leave sunflowers out of your plans. Our beginner gardeners often wonder what is the best time to plant sunflowers.

Its lovely yellow flower heads greet summer like a warm smile. Beautiful sunflower blooms have an interesting trait in that they turn to follow the sun’s passage across the sky. They move from east to west and then return to the east at night.

Sunflowers are easy to grow since they withstand heat, are insect resistant, and grow quickly in continuous blooms. In addition, they can adapt to a wide range of environmental conditions because they are native to North America.

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Best Sunflower Planting Times For Outdoors

Sunflower plants love direct sunlight, so make sure they get at least six hours of it every day. Annual plants bloom from mid – summer through the fall.

So the best time to plant sunflowers outdoors should be Spring between April and mid-July in most areas when the risk of frost is no longer a problem.

This will most likely happen in the south in mid-March or early April. During this season, you should find an area in your garden that gets a lot of sunlight.

Depending on the species, flowering time might range from 11 to 18 weeks from seed sowing.

Sunflower seeds should be sown straight into the garden or outdoor containers once the danger of spring frost has gone and soils have warmed to at least 50°F (10°C).

Planting Sunflower Seeds Successfully

Some individuals prefer to start their sunflowers indoors in pots before the end of frost and then transplant the sunflower seedlings.

However, once the soil temperatures have warmed up and there is no longer a risk of damage from frost, it is easier to plant seeds into the soil directly.

Here’s how easy it is to grow sunflower seeds into a beautiful sunflower garden. Follow the steps below to plant sunflowers outside in the mid-spring.

1. Determine The Appropriate Timing

Your last average frost date will determine when to plant sunflowers outside. Sunflower seeds can be planted 7-10 days after the last frost date.

Planting can be dispersed for several weeks after that date. Instead of planting all in one go, you can do consecutive plantings.

For example, if you plan to grow 100 sunflower plants, you can plant 25 a week for one month. You call this technique succession planting.

This provides staggered bloom times and keeps the garden beautiful for as long as possible. You are assured that there are always beautiful blooms available in your garden throughout the planting season.

planting sunflowers

2. Prepare Area Where You Are Planting

When planting sunflower seeds outside, find a location that receives at least 8 hours of direct sunlight per day. Prepare your garden beds by removing weeds.

Loosen the soil by turning or cultivating it and keep the soil moist. Select a site with well-draining soil. It should not collect rainwater.

You can amend the ground with a few shovels of animal feed or dead leaves compost before planting. You can also use a slow-release granular fertilizer that is buried at least 8 inches deep in your soil.

These tough plants thrive on even in average garden soil. However, sunflowers prefer slightly alkaline soil (pH 6.0 to 7.5) and are heavy feeders, so grow them in nutrient-rich soil.

3. Plant The Uneaten Seeds (If You Can Resist)

Sunflower seeds should be sown directly into the garden soil. Dig individual 1-inch-deep holes with a trowel, or dig a trench to plant a row of seeds.

Plant the seeds 6–8 inches apart or 12–15 inches apart, depending on the variety of sunflower.

The greater spacing is good for branching sunflower varieties with several flowering branches. Smaller spacing will produce smaller flower heads. On the other hand, the wider spacing will have bigger flower heads.

If you sow the seeds deeper than 1 inch, they might not germinate. Put a small amount of water in; most seeds require moisture to germinate.

4. Provide Ample Moisture

Because sunflower seeds contain a lot of natural oil, they require a lot of water to germinate. After planting, properly water the soil. Cover them in clear plastic wrap to keep moisture in, especially if you are starting them indoors.

Remove the plastic as soon as the seeds sprout. Maintain soil moisture through moderate watering until germination occurs.

5. Thin the Seedlings

If you sowed the seeds too thickly, don’t be afraid to thin off part of the seedlings. Proper spacing encourages the seedlings to grow faster.

Thin the sunflower seedlings to the suggested row spacing of the sunflower variety once they have their first set of true leaves. Try to dig them out gently because the cut seedlings can be relocated to a new spot in the garden if the root system is still intact.

How Long Do Sunflowers Take to Bloom?

Sunflowers come in a variety of types, and each one grows at a distinct rate. However, on average, different varieties of sunflowers take between 80 and 120 days for a plant to mature and produce seeds. 

Within the large-seeded types, the flower heads can grow to be over 12 inches in diameter. On the other hand, the tallest sunflower, such as the American Giant type, can reach more than 16 feet.

Smaller versions such as Sunsation variety have been designed for tiny spaces and pots and rarely grow taller than a foot.

Common Types Of Sunflower

The most common type of sunflower is Helianthus annuus, and its seeds are typically utilized as a bird feeder.

However, there are many varieties sunflowers, here are some of them:  

  • Mammoth – is the traditional giant sunflower, which may grow to heights of more than 12 feet. Its seeds are ideal for snacks and bird feed.
  • Sunrich Gold – This sunflower reaches a height of about 5 feet and bears a solitary 4- to 6-inch blossom. It features pollen-free flowers with golden-yellow rays and green-yellow centers. They make excellent flowers and arrangements.
  • Autumn Beauty – It has many branches and a height of up to four feet. Autumn Beauty is an excellent cut flower for floral arrangements. It comes in bronze, yellow, and mahogany colors.
  • Teddy Bear -These dwarf sunflowers are ideal for use in small gardens and containers. The flowers are fluffy, growing up to 6 inches in diameter. 

Each sunflowers that are planted as a food source can produce approximately 1000 seeds. The resultant seeds are commonly used in salads, smoothies, bread stuffing, snacks, and various other dishes.

Furthermore, the produced seed can be used to produce sunflower oil, which is used as a cooking oil. Sunflower oil is less expensive than olive oil. 

Sunflower Growing Tips For Healthy Flowers

Sunflowers are hardy plants that produce a huge number of flowers in a short period of time. Sunflower seeds germinate rapidly and develop into healthy seedlings.

Sunflowers require little maintenance once they become a mature plant. Giant sunflower blooms attract pollinators while also feeding and butterflies and birds with their mature seeds.

There are numerous approaches that may be taken to keep sunflower plants healthy and produce beautiful flowers.

Here are a few gardening tips:

1. Keep Weeds to a Minimum

Sunflower seeds require a lot of space to grow and don’t want to compete with weeds. If you want to get rid of dandelion greens, spray Roundup around the base of each seedling before putting it in the ground. This kills the weed as well as its roots.

2. Water Regularly

During the growing season, the common sunflower requires only an inch a week of water. Allow them enough time between watering sessions. When the weather gets hot, wait until it cools down at night.

planting sunflowers

3. Feed Them Correctly

Sunflower seeds need a lot of sunlight and warm temperatures to germinate. However, they will continue to generate blooms and pods throughout their life cycle after they sprout. Feed them frequently to ensure this happens.

If you used compost and organic matter to prepare your soil, you shouldn’t need any more nutrients during the growing season. Ensure that the soil is well-drained and clear of stones.

4. Keep Pests at Bay

Garden fungicide or Insecticides are not required unless the damage is severe. Keep their tasty seeds away from birds and animals and protect them from diseases. Proper plant spacing in well-drain soil is your best defense.

5. Harvest with Care

Harvest the seeds after the rear of the sunflower head has turned brown. Cut the stems close to the head off while collecting sunflower heads. Then, without shattering the pod, gently pull out the entire stem.

As the flower heads dry, loose seeds naturally fall off. Place netting or a paper sack with air holes over each head to gather as many seeds as possible.

6. Properly Store

Keep in airtight glass jars and other containers with silica gel packets. Consider adding desiccant packages to absorb extra moisture if stored outside of the refrigerator.

After harvesting, enjoy these delectable delicacies fresh or dry. It’s a tasty snack when roasted over a charcoal fire or baked in an oven.

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Final Thoughts

Sunflowers are not only gorgeous, but they are also quite useful. Sunflower seeds are high in vitamin E, which helps to protect against heart disease and cancer. Because of its healthful lipids, sunflower oil is frequently used in salad dressings.

Sunflower seeds are also high in protein,  iron, zinc, phosphorus, potassium, thiamine, riboflavin, dietary fiber, and other essential nutrients. 

Related Questions

Can you plant sunflowers in the fall?

It depends on the zone you live in.  If you live in a warmer climate , you can start planting sunflowers in late summer through early autumn. The sunflowers may not grow to their normal height due to the fading sunlight hours, so go for smaller type varieties.

Should I soak sunflower seeds before planting?

It is not necessary as it won’t speed up germination that much and requires an extra step in your process.  We always encourage you to try an experiment.  Sunflower seeds can soaked in warm water for up to 24 hours before planting.

Green Thumb Gardener
sunflowers planting
Jeremy Starke

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