Hello! You have found our illustrated guide on growing and caring for Native Sunflowers! We love all sunflowers here but the original Native species is by far our favorite. This is the original sunflower that graced the North American landscape for millennia and was domesticated about 1000 years ago by Native Americans. It is the plant that all of the other iconic annual sunflowers come from.
The many blooms that occur over a 3-4 week period provide lots of great color for a much longer time than other varieties such as Mammoth and American Giant. While Mammoth can be a great sunflower with a single, HUGE bloom it only lasts for about a week before it begins to wilt. While the regular common variety, Helianthus annuus will provide continuous blooms for about a month in the right conditions. The blooms on the native variety get to be about 6″ diameter. Did you know that each head contains about 1000 or more seeds? Each petal on the outside and in the center is actually its own unique flower that will produce a seed!
How to plant native sunflower seeds
You can direct sow the seeds around the last frost date for your garden zone (find your USDA garden zone here). Plant them in well draining soil about 3/4″ to 1″ deep (2-2.5 cm). Water the seeds and just monitor to make sure the soil is moist. You can expect germination anywhere from 5-20 days after the soil temperature warms up.
Alternatively, you can start seeds indoors 2-3 weeks before the last frost date. If you do this, grow the plant until there are a couple of sets of true leaves. Then, set the plant outside in the daytime to acclimate to the cooler temperatures for a few days, bringing it in at night. After a few days of this, you can transplant it to its final location. If you were to just plant it outside without this acclimation period you could shock and hurt young seedling.
How tall will native sunflowers get?
In general native sunflowers will grow 5′ tall (1.5 m). But in optimum conditions and fertile soil, I’ve grown them upwards of 8′ (2.4 m) tall or higher.
How much spacing for sunflowers?
Sunflowers need to be spaced about 3′ (1 m) apart. So keep your transplants at that distance, or thin seedlings as necessary. If they are packed to close together they will not grow to their full size. Also, if they are too close together they can be susceptible to fungus type diseases.
Where should you plant sunflowers?
In the sun! Sunflowers obviously like full sun (6 hrs / day). The more sun the better though. A plant that receives 12 hours of sun per day should be much taller with more blooms than a plant that only receives 6 hours of sunlight per day.
What types of soil do sunflowers like?
Sunflowers are pretty adaptable in that they can grow in a wide variety of soils. The key thing is that they need the soil to be moist, not soaked. What I mean by that is that if water pools around a sunflower after a rain, that is not good. The plant may die from root rot. So, as long as it is well drained you should be good to go.
Do I need to water my native sunflowers?
Sunflowers are heat/drought tolerant, as they evolved to live on the prairie. However, in long periods of drought they may need some additional watering. The best way to determine if they need water is to just go look at the leaves. If the leaves feel a bit dry, or the edges are turning brown then the plant is very thirsty and should be watered. Now, if you are trying to grow the tallest plants you can, then you should water frequently when there is no rain. More water will generally equal taller plants (as long as the soil can drain).
Do native sunflowers need fertilizer?
Native sunflowers generally don’t need fertilizer. In fact I’ve never fertilized mine except by mixing in some compost when I plant seeds or transplant seedlings. Now, if you are going to try to win an award for your blooms, then by all means go ahead and do as you please. But it shouldn’t be seen as necessary for a healthy plant.
Maintenance for sunflowers
Depending on the location, they may require some staking. A good healthy plant with lots of sun should be fine, but a large storm can knock over tall or leggy sunflowers that might be on the shady side.
In the fall you can cut the dried stalks down and compost them. Also, you can use the hollow stems to construct a bee hotel for the following year.
But if you want to help out the environment, leave them up all winter. I usually have a few of these grow wild in my backyard-micro-prairie, and do nothing. Birds will eat the seeds throughout the fall. I leave them up until the following Spring. Once the daytime temperatures reach 60 F (15.5 C), any insects that overwintered in the stalk should have emerged (they need a house too!). I then break the stalks off and drop them on the ground to naturally compost and act as a 1-year mulch.
There really aren’t any special diseases that will attack sunflowers as long as the soil is well drained and it isn’t in a swamp. If the leaves turn yellow though, it can mean that the plant had too much water. So check if the soil is draining. Or, if you have been watering daily – stop.
Also, make sure this plant gets the space it needs. Generally plant the flowers 3′ apart to get proper airflow and to let them reach their full potential. Poor airflow and wet conditions can create fungus.
Fauna Problems for Sunflowers
Ok, be advised that rabbits will completely decimate seedlings if they feel the urge. Also, I’ve had deer completely defoliate and even eat the stem of tall sunflower plants prior to blooming. I was amazed, these plants were already 5′ tall and the deer came right up for their midnight snack! So you may want to invest in Liquid Fence. It is the easiest method I’ve found to keep rabbits and deer away without harming the animals.
And finally, the birds and squirrels will eat the seeds as they ripen. Now, I find it fun to watch a seed head swaying in the wind when a gold finch lands on it to have lunch. Or when the flower bends down from a squirel climbing it. But if you are trying to save seeds, you will need to protect them.
How to save the sunflower seeds
After blooming the petals will wilt and the head will ‘bow’ or hang down. Over the course of about a week the head will start to turn brown. This is the time when the seed is getting a hard outer shell, and prime time for animals to attack them.
As I mentioned above, birds and squirrels looooooove sunflower seeds. So to protect them (mainly from birds) you can use old pantyhose or cheese cloth to put over the heads. It won’t harm the plant, and will dissuade and prevent birds from getting the seed.
After the seed head has dried, you can just clip it off and take the seed from it. If you are lucky the seed will fall off by gently raking your hand over it. However, if the birds have had their feast (which mine always do) then you have to basically take the head apart and separate the seed. An instructional video on this is below:
Do sunflowers spread?
An individual sunflower plant will not spread by itself, as it is an annual. That means that the plant will die after blooming and when there is a hard frost. But they will self seed for the following year. The first year I built my vegetable garden I planted two native sunflowers. The following year I had around 10 ‘volunteer’ sunflowers. Depending on conditions and how disturbed the soil is (which my garden was obviously ‘disturbed’), a single plant can make many volunteers the following year.
The state of Iowa has listed the common sunflower as a noxious weed and it is illegal to plant or sell seed there. Now that makes absolutely no sense to me – how state can make a native plantillegal! I mean, the sunflower was there for hundreds/thousands of years, and is well suited to the environment and helps the ecosystem. Why outlaw a native plant????
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