When Will Sunflowers Bloom? What to Know About Their Life Cycle

Sunflowers are easy to grow, classic flowers that bloom in early summer to late autumn. Once planted, they take around 80 to 120 days to fully bloom.

With over 70 varieties, there are annuals and perennials in the mix. You’ll have to remove the annuals when they’re done blooming, though the majority of sunflowers fall into the perennial category.

If you’re considering planting the iconic golden, brown, and green garden flower, you might be wondering when you’re going to see the payoff from your hard work. Read on to learn more about a sunflower’s life cycle and when they’re set to bloom.

Sunflower Growing Stages

Sunflowers grow in five stages: germination, vegetative, reproductive, blooming, and harvesting. Here’s a breakdown of each stage and what you can expect to see happen as you wait for those golden petals to show.

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Germination Phase

The best time of year to plant sunflowers is in late spring when the ground is warm and temperatures are between 70 to 85 degrees Fahrenheit. Depending on when you plant your seeds, you can expect the germination phase to occur between mid-April to late-May.

The germination phase begins immediately after you plant your seedlings. The entire germination phase lasts for eight days and is where the roots of your sunflowers develop in the soil.

You might start to notice what’s called a “shoot” push out of the top of the soil—this is the young sunflower that is looking for sunlight to grow further in later phases.

Vegetative Phase

After germination comes the vegetative phase. During this phase, the sunflower seedling starts to sprout tiny leaves that are four centimeters long in what is known as the “vegetative emergence” phase.

The vegetative phase begins in late-May or early June. When the first leaf sprouts, the plant is in the vegetative stage one (V1). When the second leaf comes, the plant is in vegetative stage two (V2), and so one for the rest of the leaves.

Reproductive Phase

June is normally when the reproductive phase starts. This phase starts when your sunflower starts to form a bud between the leaves that has a star-like appearance. The end of this phase is when the bud transforms into the typical sunflower look you know and finally enters the blooming phase.

Blooming Phase

Immediately at the end of the reproductive phase starts the blooming phase where you’re able to enjoy your sunflower in all its glory for about 20 days.

This is the phase where your sunflower peaks and features the bright yellow leaves, brown center, and tall stems that make a beautiful cut arrangement. This is also the phase where you can expect bees and other pollinators to flock to the flower.

Harvesting Phase

The last phase of the sunflower blooming process is harvesting the seeds to eat. This phase occurs between 110 to 125 days after planting your flowers when the leaves have turned brown and the flower is drooping.

To harvest your sunflower seeds, cut down the stalks and use your thumb to rub the loose seeds off the center head. For those that aren’t quite ready to eat, tie the stalks together with twine and then Hang them in a warm and dry area (outside) for at least five days. This should give the other seeds plenty of time to plump up and be ready to harvest.

What to Do With Sunflowers After They Bloom?

After sunflowers bloom, you can harvest the seeds to eat or prep your blooms for next growing season, depending on the variety you’ve grown. It’s also the time to deadhead your flowers to encourage new growth.

You will know it’s time to deadhead when the flowers have lost their color or are starting to wilt or droop.

Here’s how to deadhead your sunflowers for gorgeous, healthy florals:

• Locate the stems you need to deadhead.
• Use garden shears to make an angled cut a 1/2 inch above the leaves.
• Make this cut on all stems you need to deadhead.

5 Care Tips for Sunflowers

1. Remember to water seedlings daily before dropping to once a week when flowers have bloomed.
2. Plant sunflowers in a spot where they can get 6-8 hours of sunlight everyday.
3. Plant in well-drained, slightly acidic soil with a pH level between 6.0 to 6.8.
4. Apply fertilizer every two weeks.
5. Stake tall varieties of sunflowers to offer support from wind.