Everything about the Sunflower


Common Name: Sunflower

Latin Name: Helianthus annuus

Family: Asteraceae

Plant Time: late spring

Mature Size: 3–10 ft. tall, 1.5–3 ft. wide

Sun Preference: full sunlight

Soil Preference: Well-drained, acidic, alkaline or neutral soil

Bloom Time: Summer, fall

Flower Color: Yellow, mahogany, bicolors, red

Native Area: North America

Toxicity: The flowers and leafs are toxic to humans and pets

Growth Rate: up to 10 ft. in 3 months

Wildlife Value: -

Table of Contents

The sunflower plant (Helianthus annuus) is an annual plant that belongs to the family Asteraceae. It is known for its large, bright yellow flower heads that can reach up to 12 inches in diameter.

Even though sunflowers are native to North America, they are grown all over the world. These beautiful plants can grow to a height of 6 to 12 feet tall. They are pretty easy to grow from seed, and known for being hardy and tolerant of a variety of conditions. The main reason for their popularity – next to their hardness – is that the seeds from the plant can be used for food and oil.

Popular types of sunflowers:

  • Teddy Bear Sunflower
  • Mammoth Sunflower
  • ProCut Sunflower
  • Lemon Queen Sunflower


Sunflower plants can take some abuse, but they need nutrition and water. Here are our tips to keep these beautiful plants alive:

  • Soil: Sunflowers like well-draining soil (acidic, alkaline or neutral pH), so make sure they do not stand in water for a long time. Also, providing support (using a stake) for tall sunflower plants is very important, preventing them from falling over.
  • Temperature: Sunflowers prefer 70 and 78 F temperatures and are sensitive to frost and freezing temperatures, protect them if necessary.
  • Water: Sunflowers like water, so on hot summer days, you might need to water them twice a day (in the morning and late afternoon).
  • Light: Sunflowers need full sun with at least 6 hours of direct sunlight per day (just like pumpkins).


Sunflowers can be propagated by dividing the roots in the spring or fall, but the most common way is propagating by seeds:

  1. Collect seeds from ripe sunflower heads
  2. Sow the seeds in well-draining soil and full sun, in the spring
  3. Cover the seeds with a thin layer of soil, and water them regularly to keep the soil moist
  4. Germination usually takes place within a week or two, once the seedlings have at least two true leaves, thin them out so that each seedling has enough space to grow.
  5. Transplant the seedlings to their final location when they are large enough.

Common Pests

Frequently Asked Questions

How to transplant sunflower seedlings?
  1. Choose a location in your garden that receives full sun and has well-draining soil.
  2. Water the seedlings well before transplanting, this will make it easier to remove them from their containers.
  3. Carefully dig a hole in the chosen location and transplant the seedling into it, making sure to not bury it too deep or too shallow.

Can sunflowers grow in rocky soil?

Rocky soil may not provide enough nutrients for the sunflower plant to thrive, so it’s important to amend the soil with organic matter and fertilize regularly

When to plant sunflower seeds in colorado?

In general, sunflower seeds should be planted in Colorado after the last frost date in spring, when the soil has warmed to at least 50°F (10°C) and the danger of frost has passed.

Will sunflowers grow in shade?

Sunflowers require full sun to grow and produce flowers, they will not thrive in shade and may not even produce any flowers.

Are sunflowers frost tolerant?

Not even a little bit. You should protect Sunflowers from frost.

Do sunflowers have deep roots?

Sunflowers have deep roots, their taproot can grow up to 4 feet deep and their lateral roots can spread out as much as 3 feet.

How long do sunflowers bloom for?

Sunflowers bloom for about 8-12 weeks. You can see blooming sunflowers from early July to late October.