Sunflowers are commonly used in many sunny gardens since, unsurprisingly, sunflowers demand full sun. Whether you grow sunflowers for the seeds, beauty, or birds, sunflowers are a bright addition to both edible and flower gardens and will add a pop of color. If you like to plant the same types of flowers in the same place, you may be wondering, are sunflowers annuals or perennials?
There are both annual and perennial sunflowers available. Even in the Helianthus family overall, which we’ll look at in this article, you’ll find both annuals and perennials. You may be surprised to find out that you can tell which type a sunflower is by taking a close look at several parts of the flower!
Let’s take a look at how to identify annual and perennial sunflowers. We’ll also talk about the difference between them and look at some specific varieties so you can start thinking about which ones you’d like to add to your garden.
How to Identify Annuals and Perennials
Identifying annual and perennial sunflowers is easy once you know what you’re looking for. But first, let’s review the differences between the two.
Annuals complete their life cycle in one year. You can plant a seed in the spring, watch it grow through summer, and it will die soon after. The only way the annual sunflower can “come back” is by dropping seeds at the end of its life cycle.
Perennial sunflowers, on the other hand, will last for more than one year. They won’t die back completely and will return the following year from the same plant rather than seeds it dropped the previous year. Depending on your garden’s conditions and the plant’s health, a perennial sunflower can come back for several years.
Now then, let’s consider how you can tell these two types of flowers apart.
When you leave sunflowers to do their thing, you’ll notice that perennial sunflowers typically come back in early spring, while annual sunflower seeds won’t germinate until late spring. Perennials are more established and can withstand cooler temperatures, while seeds are more delicate and have to wait for the soil to warm up enough before sprouting.
You can determine what type of sunflower seeds you have by waiting to see if they bloom later in the year. Annual sunflowers bloom the same year they’re planted, while perennials won’t develop blooms until the second year. Since perennials will come back, they take a year to develop roots and stems to be fully established before blooming.
If you have multiple types of sunflowers growing in the same space, their growth habits are the easiest way to tell which is which. Fast-growing annuals germinate quickly once they’re in the optimal temperature and will continue to grow quickly through the growing season and into early fall. Perennials germinate and grow slowly since they’re playing the long game and intend to stick around for a while.
If you have full-grown flowers that are well established, look at their stems. Annuals will have one thick main stem and may have several smaller ones shooting off of it. Perennials are clump-forming and will have several stems coming out of the ground rather than just one.
Perhaps one of the most undeniable ways to determine if your sunflowers are annual or perennial is to look at their roots. It’s not necessarily the most convenient way to tell them apart, but a little bit of digging will be telling.
Annual sunflowers are often tall and mighty but here for a short time, so they grow a deep taproot with smaller, thin roots coming off of it. Perennials are here to stay and have to survive winter, so they develop rhizomes for storage to keep them alive. You won’t have to dig too far to find the rhizomes, so it should be fairly easy to find them.
Seeds are probably the more difficult way to determine what kind of sunflower you have, but you can use them to make a guess.
Annuals tend to have large seed heads, which is typically the largest part of the flower. The seeds are also sizable. If you think about it, it makes sense for the flowers to be this way since they spread by dropping seeds. The plant needs to focus on the seeds so the species can live to see another day.
Perennial varieties are a bit trickier. Heirloom perennials generally have small seed heads and seeds since the plants can spread by the roots. Heirlooms are the “original” type of flower and haven’t been bred to have special traits. But, some hybrid varieties, which are a cross between two different species, may have bigger seeds. The seed heads will likely remain small, but that doesn’t necessarily mean it’ll always be the case.
We’re going to dive into a few different species of annual Helianthus sunflowers so we can see how many different annual varieties there are.
The beach sunflower, Helianthus debilis, is a heat-loving variety that can be either annual or perennial. It’s an annual in places where it gets cold enough to freeze, so we listed it here. But, if you never have freezing temperatures where you live, this flower will come back every year.
This sunflower is short and can act as a ground cover. The flower heads are small and have yellow flower petals. It’s beautiful in areas where you can let it take over an area.
The common sunflower, or Helianthus annuus, is arguably the most popular sunflower available. It comes in many colors and sizes, and there’s sure to be a hybrid for everyone to love. They come in many beautiful warm shades besides yellow, including brown, red, orange, and white.
The following list is a selection of hybrids of Helianthus annuus. They have similar traits regarding height and seed head width, but they’re all incredibly unique despite being the same species.
- Evening Sun: The Evening Sun is aptly named for its fiery reddish-orange petals that have spots of yellow and a brown center. The Evening Sun looks painted and can grow up to 8 feet tall and just over 2 feet wide.
- Floristan: The Floristan is smaller, reaching only 5 feet tall and 1.5 feet wide, but has unique coloration. The reddish-purple and pale yellow ombre petals surround a brown and yellow middle.
- Firecracker: The Firecracker has a dark brown seed head surrounded by light brown and yellow petals. It’s a dwarf variety that only reaches 3 feet tall and 1 foot wide, making it a good choice to grow in a container on the patio.
- Russian Mammoth: The Russian Mammoth is one of the largest sunflower varieties, reaching up to 12 feet tall and 4 feet wide! It has the typical coloration of Helianthus annuus and is typically grown for its edible seeds. Some gardeners season and grill the seed head and eat it like corn on the cob.
- Teddy Bear: The Teddy Bear hybrid is undoubtedly unlike the others. Rather than the typical look of sunflowers, this one boasts a fluffy flower that’s soft to the touch. It’s a short variety that only reaches 3 feet tall and 1.5 feet wide.
Helianthus argophyllus, or the silverleaf sunflower, looks a lot like the beach sunflower but can grow up to 6 feet tall. Its foliage is slightly silvery, making the flowers stand out even more.
Now, let’s take a look at some perennial species. Remember, these are the kinds of sunflowers that will come back every year as long as they’re grown in the appropriate hardiness zone. Perennial varieties may get out of control and require pruning every few years since they can spread by rhizomes and by dropping seeds.
Helianthus mollis spreads by rhizomes just like other perennial flowers, but they can also drop their seeds and begin new plants. They have small flower heads, small seeds, and rounded yellow petals and only grow up to 4 feet tall. This is a native species in North America, so they’re great to add to gardens or natural areas if you want to provide native plants for pollinators.
Helianthus tuberosus is another variety native to North America. This is a unique variety to grow not only for its bright yellow flowers but for the edible rhizomes that you can cook up like you would a potato. If you want to plant these to eat the tubers, make sure to plant enough so you can leave some rhizomes behind to bring the flowers back next year.
Helianthus maximiliani can reach up to 10 feet tall. The flowers are bright yellow, and the seed heads are small and brown. The petals are slender and pointed, and the foliage has a slight grey tone to it. It’s a drought tolerant variety, so it’s great for gardens that don’t get much water.
Helianthus angustifolius, the swamp sunflower, has small but striking yellow flowers with dark centers. The flowers are grown in clusters at the top of each stem, and it has several thin leaves along the stems. These certainly look different than your typical sunflower, so they’re a unique addition to any garden.
Helianthus occidentalis, known as the western sunflower, is easily recognizable due to its yellow-orange seed head, slender yellow petals, and bare stems. Most of the foliage is on the bottom of the plant, leaving the flower heads alone above them. These are short and small sunflowers, measuring up to 4 feet.
Helianthus salicifolius, or the willow-leaved sunflower, can grow up to 10 feet tall and have bright yellow petals and reddish-brown centers. The leaves are long and wispy, much like a willow tree, giving this flower its name. This flower is an excellent addition to cut flower gardens since these flowers look beautiful in a vase.
Frequently Asked Questions
Q: How do I know if my sunflower is annual or perennial?
A: You can tell if your sunflowers are annual or perennial based on a few key features, including their roots, seed heads, and stems. An annual will have a single deep taproot, one main stem with others coming off of it, and usually, but not always, has a large seed head with large seeds. Perennials have rhizomes, several smaller stems, and typically have small seed heads with small seeds.
Q: What to do with a sunflower when it dies?
A: When an annual sunflower dies, you can dry out the seeds to save for next year, or you can eat them. The flower won’t come back, so you should remove it from your garden. For perennials, cut the spent flowers and dispose of them. You’ll likely see more sunflowers bloom this year and the plant will come back next year.