Food Growing / Garden / Plants

Wild Sunflower: Weed or Worthy?

Wild or common sunflower (Helianthus annuus) is a native plant in most of North America and all of the United States. This is the plant from which we have bred large annual garden sunflowers grown for cut flowers, seeds, and pure bragging rights.

Wild Sunflower. Image by Amber Avalona from Pixabay

Cultivated sunflowers tend to be loved and prized by all, while their wild ancestor tends to be considered more of a weed. I think this is mostly because, as designed by nature, they show up by themselves; and an unplanted plant usually equates to “weed” for most people.

In Iowa, the plant is listed as a noxious weed. Now, Iowa is my home state, so I feel I have a right to be a little critical of it. And here it is… everything but corn and soybeans are noxious weeds in Iowa. That’s a slight exaggeration. They also grow tomatoes and zucchini. I’m kidding of course, but I do struggle with many noxious weed designations.

Should You Let Wild Sunflowers Grow?

So should you let them grow in your garden? Will they take over? Wild sunflowers do prefer disturbed soil, as most annuals do. If you allow wild sunflowers to grow in a garden that gets continually tilled or dug, they will be very persistent. You might get a whole bed of them popping up the next spring. This is why they are noxious in Iowa, practically the entire state is tilled over every year.

Iowa, in a nutshell

However if you have a garden full of perennials that doesn’t get disturbed, you can be happy to let annual sunflowers make an appearance. They attract many species of birds, who eat their seeds, and their cheery yellow flowers are a welcome treat in the late summer as they tower above the rest of the garden. In an undisturbed garden, they will struggle to gain any traction. Enjoy them while they act as a natural bird feeder, as they won’t last too long. In fact, as it usually goes, the more you appreciate them, probably the more likely it will be that they will fade away.

Wild sunflower makes a wonderful free and natural bird feeder.

The seeds of the wild sunflower are edible, but they are very small for us to deal with, as most wild ancestors of seeds tend to be (another example is wild amaranth vs. cultivated). The flowers are pretty, but in a much simpler, more modest way than the cultivated sunflowers that are often such show-stoppers. But let me tell you, there is much, much more to say about the common sunflower.

Plant Characteristics and Uses

So why else would it be beneficial to allow wild sunflower to take up precious space in your garden? Here’s the lowdown on this extremely useful and beneficial plant.

VarietyThis plant has been bred to exhibit many different features from height, to large seeds, to oil production.
Common NameCommon sunflower or Wild sunflower
Height1.5 to 8 ft. 
Foliage ColorGreen
Flower ColorYellow
Bloom TimeJuly — October
PollinationSelf-fertile, insects
USDA Hardiness Zone2-11
NativeCanada, US, Northern Mexico
Aggressive behaviorCan be aggressive in disturbed soils
InvasiveNo, not in its native range
Sun RequirementsFull sun
Drought TolerantYes
pHWide range
Nitrogen FixationNo
Root StructureSingle tap root with smaller secondary roots
Biomass ProducerMedium
Soil PenetrationYes
Edible Leaf/StalkYes: young shoots, stalks raw or cooked, leaves raw or cooked, or tea
Edible FruitsNo
Edible SeedYes: raw, toasted, or pressed for oil
Edible RootYes: raw, cooked, or tea
Edible FlowersYes: petals raw or cooked
Harvest TimeGrowing season for root and greens, fall for seeds
Storage timeRaw seeds: 2-3 months at room temperature, 1 year refrigeratedSeeds roasted and in shell: 4-5 months at room temperature, 1 year refrigerated
Poisonous PartsNo
MedicinalYes, astringent, diuretic, expectorant
Larval HostSunflower moth. Considered a pest on cultivated sunflowers, but these are wild plants. Allowing these plants to grow, and then allowing sunflower moths to lay eggs and hatch on your plants will attract parasitic wasps and flies. Up to 50% of these moth larvae will be parasitized. Then those insects will emerge, increase the population of beneficial insects in your area, and go on to parasitize other possible “pests” in your garden.
Wildlife FoodYes, especially pollinators and birds
Wildlife ShelterYes, especially insects and birds
Pest ConfusionNo, usually fragrant plants handle this job
Fragrance Pleasant to HumansFlowers not fragrant
Deer ResistantYes. Deer might eat the young shoots, but they will just sprout with multiple shoots from the severed spot.
Beauty (as commonly perceived by a majority of urban folks)Medium
DyeBlack or dark blue from seeds, yellow from flowers
Tolerates JugloneYes, but they might not get enough sun under the crown of a walnut or pecan tree
Allelopathic (stunts growth of some surrounding plants)Has shown some allelopathic tendencies to some surrounding plants. I have not personally found evidence of this in my garden, but that is merely anecdotal.

How Do You Know if You Have Wild Sunflowers?

I remember when I first started learning about plants, I would find botanical descriptions of plants that made no sense to me and just skip over them. They still don’t make sense to me — a bunch of subjective adjectives won’t help me one bit. What did help me was looking at lots of images. Specifically, when you are trying to figure out what new plant nature brought into your yard, posts and pages describing said plant as a weed tend to have the least beautiful and most helpful pictures of all. Here is a link to a University of Missouri page describing this “weed.” It has very helpful pictures.

Photo of a wild sunflower seedling from University of Missouri

When you see little seedlings like this in the spring, leave them, you may have received a free, super-useful gift from nature! But keep an eye on them, because it’s easy to misidentify seedlings.

So you decide whether these properties are well-suited or functional enough for your property. For our yard, we choose to enjoy the many benefits of wild sunflowers.