How to Prune Sunflowers

Co-authored by Monique Capanelli

Last Updated: February 28, 2024 Fact Checked

Annual sunflowers (plants that only bloom once) typically do not need any pruning. However, sunflowers that are growing in groups may need to be trimmed to keep from knocking one another over. By comparison, perennial types of sunflowers will occasionally require a trim. Pruning helps these plants maintain a neat and tidy appearance during the summer months when they tend to get unruly. To prune your plants correctly, you will first have to know when to prune them.

Method 1

Method 1 of 2:

Knowing When to Prune

Download Article

A good general rule for pruning perennial sunflowers is to cut them down to half their size in the late spring or early summer. Then, reduce their size again by a third in June or July.^{[1]
X
Research source}
2
Keep your warm climate in mind. Gardeners from warmer climates should prune Maximillian, swamp (Helianthus angustifolius), and willow leafed (Helianthus salicifolius) sunflowers to two-thirds of their original height in June.^{[2]
X
Research source}
- This procedure will keep these potential giants at a more manageable size and eliminate the need to stake them.
Advertisement
3
Avoid pruning after the first blooms appear. Most perennial sunflower species bloom between mid and late summer. Gardeners should keep an eye on their plants at such times and refrain from pruning them after their buds start forming.^{[3]
X
Research source}
- However, the rules are slightly different for late summer blooming varieties. Late summer blooming types should be pruned back when they reach between 1.5 to 2 feet (0.5 to 0.6 m) in height, because they will recover in a few weeks and bloom regardless of the cuts.
4
Prune very tall varieties of sunflowers in June or July. Maximilian sunflowers (Helianthus maximiliani) and Mexican sunflowers (Tithonia diversifolia) should be trimmed in June or July. This will reduce the sunflowers’ size from their typical height of 9 feet (2.7 m) or greater to a much more manageable 4 feet (1.2 m).^{[4]
X
Research source}
- Maximilian sunflowers can also be left standing through the winter months as food for the birds. If you choose to leave your tall sunflowers for the birds, they can be cut to the ground in the early spring to prepare the plant for new growth.
Annual sunflowers can be trimmed back to the ground when they start to dry out and turn brown. They will not bloom again so many gardeners choose to remove them from their gardens entirely.^{[5]
X
Research source}

Method 2

Method 2 of 2:

Pruning Your Sunflowers

Download Article

1
Sterilize all pruning equipment prior to use. Sterilizing your pruning equipment is particularly important if you have dealt with some diseased plant parts recently. This will prevent any lingering bacteria or germs from unintentionally being spread throughout the garden.^{[6]
X
Research source}
- Prune sunflowers with sharp bypass hand pruners or hedge shears.
2
Trim away unhealthy parts of the plant first. Trim any sick, weak, damaged, crossing, or dead branches off of your plant before starting into any sort of heavy pruning operation.^{[7]
X
Research source}
- Diseased parts should be kept out of the compost bin to prevent the ailment in question from being transmitted to any other plants. These bits of debris will instead need to be burned or bagged up and left for the local waste crews to collect.
3
Prune your perennials so that they take on the desired shape. Once you have cut away all of the unhealthy branches, you can choose to prune your perennial sunflowers for shape.^{[8]
X
Expert Source

Monique Capanelli
Plant Specialist

Expert Interview. 22 September 2020.}
- Some people prefer to only prune away damaged parts of the plant so that their sunflowers can take on a more wild look.
Water the sunflowers regularly after pruning to help them recover from the stress of being trimmed back. Give them enough water to thoroughly soak the soil every time the top inch of the soil becomes dry.^{[9]
X
Research source}

Expert Q&A

Search

Add New Question

Question

How do I prune a tree?

Monique Capanelli
Plant Specialist
Monique Capanelli is a Plant Specialist and the Owner and Designer for Articulture Designs, an innovative design firm and boutique in Austin, Texas. With over 15 years of experience, Monique specializes in interior botanical design, living walls, event decor, and sustainable landscape design. She attended the University of Texas at Austin. Monique is a Certified Permaculture Designer. She provides plant and botanical design experiences, from small gifts to entire transformations, to shoppers as well as commercial clients including Whole Foods Market and The Four Seasons.

Monique Capanelli

Plant Specialist

Expert Answer

You should remove the dead parts of the tree and cut the branches that have grown too long and are spoiling the shape.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 4 Helpful 11
Question

What is the advantage of pruning the trees?

Monique Capanelli
Plant Specialist
Monique Capanelli is a Plant Specialist and the Owner and Designer for Articulture Designs, an innovative design firm and boutique in Austin, Texas. With over 15 years of experience, Monique specializes in interior botanical design, living walls, event decor, and sustainable landscape design. She attended the University of Texas at Austin. Monique is a Certified Permaculture Designer. She provides plant and botanical design experiences, from small gifts to entire transformations, to shoppers as well as commercial clients including Whole Foods Market and The Four Seasons.

Monique Capanelli

Plant Specialist

Expert Answer

Pruning helps to maintain the shape and size of a tree. It also stimulates fuller growth.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 3 Helpful 5
Question

One sunflower plant has five blossoms. Should I prune down to only one or two?

Community Answer

You can if you'd like, but you may also leave all five there.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 9 Helpful 24

See more answers

Ask a Question

200 characters left

Include your email address to get a message when this question is answered.

Submit

Tips

Once gardeners are done with their trimming, they should oil their garden tools to prevent them from getting rusty. The garden implements should then be put away in a safe place so that they can be found again easily for later use.

Thanks
Helpful 0 Not Helpful 0
Snipping off the top buds on these plants is a somewhat effective method of reducing the plant height. Although the side buds will form blooms, the plant won’t get as tall.

Thanks
Helpful 1 Not Helpful 0

Submit a Tip

All tip submissions are carefully reviewed before being published

Submit

Thanks for submitting a tip for review!

Warnings

Gardeners should be careful when they go to prune their plants because annual sunflowers that are cut will not produce new blooms.

Thanks
Helpful 7 Not Helpful 2