How to Grow Sunflowers

It’s hard to see a sunflower blooming and not smile. Sunflowers are a great addition to a summer garden. Take advantage of the unique characteristics of sunflowers and put them to work in your garden. Learning how to grow sunflowers is easy, and finding new ways to incorporate them into your garden is a lot of fun. Here are 7 of my favorite reasons to grow sunflowers.

How to Grow Sunflowers

1. Sunflowers are easy to grow.

Sunflowers are one of the easiest flowers to grow. Drive along a freeway in certain parts of the country and you will see wild sunflowers growing in compacted dirt on the side of the road. Plant sunflower seeds about an inch deep in loose soil; the roots like to grow deep and wide. Sunflowers can grow in poor soil, but richer soil will produce larger blooms. The amount of space to leave between plants depends on the size of the flower. Small blooms can be spaced about 6 inches apart, but the largest blooms need about 3 feet between each plant.

Tip: When it’s time to remove the sunflower, don’t pull it out; cut the stem a few inches above the dirt. In a month or two, roots will decay and stem will easily come out of the ground without removing excessive amounts of dirt with the roots.

2. Sunflowers make a great trellis for other plants.

Sunflowers make a great trellis for other plants. Sunflowers grow tall and the many vining plants of summer (cucumbers, squash, melons) often find the tall, straight trunk and climb. This natural trellis helps keep the plants up off the ground, and growing plants vertically encourages healthier plants. This is similar to a “Three Sisters” garden where there is a beneficial relationship between corn, beans, and squash. Plant sunflower seeds near vining plants and plan for the vines to climb the sunflower.

3. Sunflowers provide shade in the garden.

Once you learn how to grow sunflowers in your garden, they often come back year after year. As they sprout, determine which ones to let remain to provide shade for your garden. The multi-branching varieties are often great for this. Prune lower leaves to provide access in and around sunflowers, and leave higher leaves and blooms to shade other plants.

Want more ideas for providing shade in the garden? This article shares my favorite tips.

4. Sunflowers can attract colorful birds to your yard.

Here in Arizona, if you have sunflowers and like to get up early you may be rewarded by visits from Love Birds. They show up as early as 5 a.m. in my yard during the summer. I’ve spotted ten in my yard at one time. When they are done, the yellow finches show up and enjoy the seeds and the leaves too.

There are always plenty of sunflowers, so I don’t mind sharing with the birds. It’s one of my favorite parts of summer mornings. To attract visitors all year, dry sunflower heads and attach to fences in the winter months to feed the birds.

5. Sunflower seeds are delicious and easy to grow.

Birds will eat any kind of sunflower seed, but if you are growing them to enjoy yourself, look for confection varieties for their plump delicious seeds. Varieties to try are Gigantus, Mammoth, Snack Seed, or Titan. For more information about growing and harvesting edible sunflower seeds, read this article I wrote for Kellogg Garden.

Signs that the sunflower seeds are ready to harvest:

The flower petals dry out and begin to fall off.
The back of the flower begins to turn from green to yellow and eventually brown.
The seeds are plump and developed.
Left to dry on the stalk, the seeds turn from white to brown.

6. Sunflowers take the heat.

Arizona summers can be brutal. The sunflowers don’t mind – in fact, they seem to thrive on neglect. Pops of yellow flowers brighten up a summer yard. Learning how to grow sunflowers is an easy way to add color and variety to a summer garden and yard. In Arizona, you can plant sunflowers from February through July, so you can enjoy the blooms nearly year-round.

7. Learn how to grow sunflowers as cut flowers.

Single-stemmed types produce one flower per seed. The bloom size of single-stemmed types is determined by the planting distance between plants. If you leave more space, the blooms will be larger.
Branching types have many flowers per seed. You should allow 1-2 feet between branching varieties.
Look for pollenless varieties for cut sunflowers. Varieties to try are Sunrich and Procut for single stem, and Teddy Bear and Moulin Rouge for branching varieties.
Both types of sunflowers are good for cut flowers, depending on the sizes of blooms you prefer.
Harvest the stem just as the petals begin to open; sunflowers will continue to bloom once cut.
Remove all leaves below the top bloom.
Depending on the variety, cut blooms can last from 1-2 weeks.

Want more information about gardening in Arizona? This blog post shares 7 tips for how to grow a vegetable garden in Arizona.

Arizona annual flowers planting guide helps you learn when to plant flowers in Arizona, and whether to plant seeds or transplants.

Sue Hayman

Wednesday 27th of April 2022

Thanks for this article! I am having an issue with insects on my sunflowers. They are small, kind of buff colored and on the top of the leaves. I’m not sure what to use to control them. I hand wipe them to remove them and have sprayed with a water and dish soap mixture. Do you recommend a certain spray to control these? I have also noticed green flying insects around them. I leave those alone.

Thanks! Sue

Angela Judd

If they aren't damaging the plant too much, I wouldn't worry about them. If they are causing damage, you could spray them off with water. That is as much as I would recommend doing.

eva

Wednesday 9th of February 2022

Hola. I'm wondering if a five gallon container is big enough to grow sunflowers (including Mexican Sunflowers)? If so, how many sunflower seeds per pot? Thank you so much for the beauty & generosity of your website! Take care!

Thursday 10th of February 2022

@Angela Judd, Muchas gracias!

Hi! Yes that would be large enough. For large sunflowers and Mexican sunflowers I would thin to one plant. For smaller varieties you could have 3-5 depending on the size.

Michelle

Monday 5th of April 2021

My seeds started out well and now two of them have been attacked. I checked on them this morning and it was fine but this afternoon it looks like something has strangled it. I had this happen last week too. Any ideas??

Tuesday 6th of April 2021

Could be pill bugs or birds. Both can be problems. Protect from birds with netting. Pill bugs or other insects can be tricker - you can wrap the stems with newspaper as a barrier.

Annie Rightnour

Friday 24th of July 2020

Thank you so much for this great information! You mentioned that sunflowers do better in rich soil- do you have any suggestions for preparing the soil before I plant? I am preparing to attempt to transplant sunflower seedlings I started indoors (our rabbits and squirrels here kept eating them up when I started them outside earlier this summer). I live here in Phoenix. :)

Adding compost to the soil is always a good choice. Best of luck to you.

Wright

Wednesday 1st of July 2020

Is there a sunflower variety that is particularly best suited for the Phoenix, AZ summer heat?

Nearly all varieties do really well here. Choose the one you like. If there is one that you love one year, be sure to save seeds so you can plant it again.