Add color and whimsy to almost any garden space with these low-maintenance, fast-growing, sun-loving blooms.
Basically, if your garden space has full sun and well-drained soil, you might grow sunflowers.
Use small varieties inlandscape bedsfor a touch of whimsy in midsummer.
Credit: Bill Stites
It should be noted thatHelianthus annuusis considered an invasive weed in parts of Nevada.
In Iowa, the common sunflower is classified as a noxious weed.
Before planting in these areas check with your local garden extension service office or cooperative.
Credit: Bill Stites
In the garden, plant your sunflower seeds about 1 inch deep and about 6 inches apart.
Well-spaced seedlings are key to strong, upright sunflowers later in the season.
Mature sunflowers are likely to settle with their blooms facing east.
Credit: Bill Stites
Annual sunflowers are also drought-tolerant but will bloom better if watered regularly.
When your sunflower is young, water it deeply about once a weekor less if the weather is wet.
This schedule will encourage your plants roots to grow healthy and strong.
Be mindful of overwatering as that can lead to root rot and other problems.
Temperature and Humidity
Sunflowers are somewhat cold tolerant, but dont fare well in frost conditions.
For that reason, its best to plant them only after the danger of frost has passed.
Credit: Bill Stites
The sweet spot for sunflowers is when temperatures stay between 68- and 80-degrees Fahrenheit.
Excessive or incorrect use of fertilizer may cause the plants stalks to droop or break.
Cut the stems at a 45-degree angle and see to it each bloom has approximately 24 inches of stem.
Credit: Charles Mann
After 6 to 24 hours, you might move them to your bouquet or arrangement.
This will help persuade lush growth.
Potting and Repotting
Sunflowers make great container plantsespecially the dwarf varieties.
Credit: Bill Stites
If you are planting multiple sunflowers, place the seeds approximately 4 inches apart.
Cover the seeds with more potting mix, tamp the soil down, and water again.
How to Propagate Annual Sunflower
The easiest way to propagate annual sunflowers is via seed.
Credit: Jane Booth Vollers
Pests and Problems
Sunflowers are susceptible to issues with sunflower moths.
Otherwise, insect-punch in pests tend to leave sunflowers alone.
Deer are also prone to nibbling on the new and established flower heads.
Credit: Alise O’Brien
Use deer-resistant fencing or plant a barrier ofdeer-resistant shrubsto keep them at bay.
Sunflowers can also have issues with root rot, powdery mildew, downy mildew, and rust.
‘Italian White’ Sunflower
Helianthus’Italian White' bears creamy-white flowers on 5-foot-tall plants in zones 4-9.
Credit: Eric Roth
Sunbeam Sunflower
Helianthus’Sunbeam' bears pollenless yellow flowers with yellow centers on 6-foot-tall plants in zones 3-11.
‘Teddy Bear’ Double Sunflower
ThisHelianthusvariety bears interesting double yellow flowers on dwarf 3-foot-tall plants.
Companion Plants for Annual Sunflower
Castor Bean
Plant acastor beanand then stand back.
Credit: Kritsada Panichgul
This is one of the fastest-growing, giant annuals in the garden, rivaled only perhaps by giant sunflowers.
It’s a great plant to grow with kids.
Be careful, though.
Credit: Eric Roth
The seeds are extremely toxic.
You will often find fields of corn surrounded by rows of sunflowers for this very reason.
Kiss-Me-Over-the-Garden-Gate
Try this delightful flower togrow something differentand striking in your garden.
Credit: Peter Krumhardt
It’s great for creating a quick privacy screen or making a bold statement in big containers.
Kiss-me-over-the-garden-gate can, however, self-seed in the garden.
Zinnia
Want fast color for just pennies?Plant zinnias!
Credit: Peter Krumhardt
And it will happen in just weeks.
you could also find special seed blends for cutting, for attracting butterflies, and more.
To maximize butterfly visitation, plant lots of tall, red or hot pink zinnias in a large patch.
‘Big Red’ is especially nice for this and the flowers are excellent for cutting.
Frequently Asked Questions
Yes, but not all varieties will produce viable seeds.
There are a number of sterile cultivars that have been developed to produce long-lasting blooms, but no seeds.
These cultivars are commonly used in the cut flower industry.
These sunflowers form a single large flower head atop a stem that may reach 10 feet or more.
Store the head in a dry, well-ventilated place where the seeds can fully mature.
Look at the seed label (if you have it).
Annual sunflowers tend to bloom a little later in the spring and will grow much faster than perennials.
Annuals also grow their flowers atop one main stalk as opposed to forming clumps of stems and blossoms.
This effect has downsides, too.
Since sunflowers are allelopathic, they can deter desired plants (like grass) from growing nearby.
Peas and sweet peas, however, are okay to grow as a companion plant to sunflowers.
Checklist of the Non-native Plants of Southern Nevada.
University of Nevada, Reno, College of Agriculture, Biotechnology & Natural Resources Extension.
Hartzler B, Anderson M. Common sunflower.
Common sunflower | Integrated Crop Management.
Accessed August 5, 2024. https://crops.extension.iastate.edu/encyclopedia/common-sunflower.
UF/IFAS Extension Gardening Solutions.
