Sunflowers are widely used in many sunny gardens as sunflowers unsurprisingly require full sun. Whether you grow sunflowers for the seeds, the beauty, or the birds, sunflowers are a brilliant addition to both edible and flower gardens, adding a touch of color. If you want to plant the same types of flowers in the same place, you may be wondering whether sunflowers are annual or perennial.
There are both annual and perennial sunflowers. You can also find both annuals and perennials in the Helianthus family as a whole, which we consider in this article. You will be surprised that you can tell what type of sunflower it is by looking closely at several parts of the flower!
Let's take a look at how to spot annual and perennial sunflowers. We'll also talk about the differences between them and look at some specific strains so you can think about which ones to add to your garden.
How to recognize annual and perennial plants
Are sunflowers annual or perennial? Source: Dovima-2010
Identifying annual and perennial sunflowers is easy when you know what to look for. But first, let's check out the differences between the two.
Annuals go through their life cycle in one year. You can plant a seed in the spring, watch it grow over the summer, and it will die soon after. The only way the annual sunflower can "come back" is to drop seeds at the end of its life cycle.
Perennial sunflowers, on the other hand, last longer than a year. They do not die off completely and return from the same plant the following year instead of seeds they lost the previous year. Depending on the conditions of your garden and the health of the plant, a perennial sunflower can come back for several years.
Now let's see how you can tell these two types of flowers apart.
Germination time
If you let sunflowers do their thing, you'll find that perennial sunflowers usually come back in early spring, while annual sunflower seeds don't germinate until late spring. Perennials are more established and can withstand cooler temperatures, while seeds are more sensitive and have to wait for the soil to warm up sufficiently before they sprout.
Blooming
You can tell 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 are planted, while perennials don't bloom until the second year. Since perennials will return, it will take them a year to develop roots and stems before they bloom.
growth
If you have multiple types of sunflower growing in the same room, their growing habits are the easiest way to tell which is which. Fast growing annual plants germinate quickly once they are at the optimal temperature and will continue to grow rapidly through the growing season and into early fall. Perennials germinate and grow slowly as they play the long game and intend to stay for a while.
When you have fully grown flowers that are well established, take a look at their stems. Annuals have a thick main trunk and can shoot several smaller ones. Perennials form clumps and have multiple stems emerging from the ground instead of just one.
root
One of the most indisputable ways to tell if your sunflowers are annual or perennial is to look at their roots. It's not exactly the most convenient way to tell them apart, but a little digging will be revealing.
Annual sunflowers are often large and powerful, but only here for a short time, creating a deep taproot from which smaller, thin roots extend. Perennials are here to stay and need to survive the winter, so they develop rhizomes for storage to keep them alive. You don't have to dig too far to find the rhizomes, so finding them should be pretty easy.
Seeds
Seeds are probably the more difficult way to determine what type of sunflower you have, but you can use them to make a guess.
Annuals usually have large seed heads, which usually make up most of the flower. The seeds are big too. If you think about it, it makes sense for the flowers to be like this, as the falling of seeds will spread them. The plant needs to focus on the seeds for the species to survive for another day.
Perennial varieties are a little more difficult. Heirloom perennials generally have small seed heads and seeds because the roots allow the plants to spread. Heirlooms are the "original" type of flower and were not bred for special properties. However, some hybrid strains that are a cross between two different species can have larger seeds. The seed heads will likely remain small, but that doesn't necessarily mean they will always be.
Annual sunflowers
We're going to be diving into a few different types of annual Helianthus sunflower so we can see how many different annual varieties there are.
Beach sunflower
Helianthus debilis. Source: Giveawayboy
The beach sunflower, Helianthus debilis, is a heat-loving variety that can be either annual or perennial. Places where it gets cold enough to freeze is annual, so we've listed it here. But if you never have freezing temperatures where you live, this flower comes back every year.
This sunflower is short and can serve as a ground cover. The flower heads are small and have yellow petals. It's nice in areas where you can let it take over an area.
Common sunflower
Helianthus annuus. Source: anro0002
The common sunflower or Helianthus annuus is arguably the most popular sunflower on the market. It's available in many colors and sizes, and there's sure to be a hybrid out there that everyone can love. In addition to yellow, they come in many beautiful warm shades, including brown, red, orange, and white.
The following list is a selection of hybrids of Helianthus annuus. They share similar characteristics in terms of height and seed head width, but despite being the same species, they are all incredibly unique.
- Evening sun: The evening sun is aptly named for its fiery reddish-orange petals that have yellow spots and a brown center. The evening sun looks painted and can get up to eight feet high and just over two feet wide.
- Floristan: The Floristan is smaller, only 5 feet tall and 1.5 feet wide, but has a unique coloring. The reddish-purple and pale yellow ombre petals surround a brown-yellow center.
- Fireworks: The firecracker has a dark brown seed head surrounded by light brown and yellow petals. It is a dwarf variety that grows to only 3 feet tall and 1 foot wide, which makes it a great choice for growing in a container on the patio.
- Russian mammoth: The Russian mammoth is one of the largest varieties of sunflower, growing 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 different from the others. Instead of the typical look of sunflower, this one offers a fluffy flower that is soft to the touch. It is a short variety that grows to only 3 feet tall and 1.5 feet wide.
Silver leaf sunflower
Helianthus argophyllus. Source: CWR
Helianthus argophyllus, or the silver leaf sunflower, looks very similar to the beach sunflower, but can grow up to 6 feet tall. Its foliage is slightly silvery, which makes the flowers stand out even more.
Perennial sunflowers
Now let's look at some perennial species. Remember, these are the types of sunflowers that will come back every year as long as they are grown in the appropriate hardiness zone. Perennial varieties can get out of control and need to be pruned every few years as they can spread through rhizomes and through falling seeds.
Ashy sunflower
Helianthus mollis. Source: Peganum
Helianthus mollis, like other perennial flowers, spreads through rhizomes, but it can also drop their seeds and start new plants. They have small flower heads, small seeds, and rounded yellow petals, and only grow to 4 feet tall. This is a native species to North America, so they make great additions to gardens or natural areas when you want to provide native plants for pollinators.
Jerusalem artichoke
Helianthus tuberosus. Source: anro0002
Helianthus tuberosus is another variety native to North America. This is a unique variety that is grown not only for its bright yellow flowers, but also for the edible rhizomes that you can cook like a potato. If you plan to plant these to eat the tubers, make sure you plant enough so that you can leave some rhizomes behind to bring the flowers back for the next year.
Maximilian sunflower
Helianthus maximiliani. Source: Matt Lavin
Helianthus maximiliani can grow up to 3 meters high. The flowers are bright yellow and the seed heads are small and brown. The petals are slender and pointed and the foliage is a slight shade of gray. It's a drought tolerant strain, so it's great for gardens that don't get a lot of water.
Swamp sunflower
Helianthus angustifolius. Source: eleanord43
Helianthus angustifolius, the marsh sunflower, has small but striking yellow flowers with dark centers. The flowers grow in clusters at the top of each stem and have several thin leaves along the stem. These certainly look different from your typical sunflowers, making them a unique addition to any garden.
Western sunflower
Helianthus occidentalis. Source: Wackybadger
Known as the western sunflower, Helianthus occidentalis is easily identified by its yellow-orange seed head, slender yellow petals, and bare stems. Most of the foliage is on the underside of the plant, leaving the flower heads alone above. These are short and tiny sunflowers that measure up to 4 feet.
Willow leaf sunflower
Helianthus salicifolius. Source: douneika
Helianthus salicifolius or the willow-leaved sunflower can grow up to 3 meters high and has bright yellow petals and reddish-brown centers. The leaves are long and thin, similar to that of a willow, which gives this flower its name. This flower makes an excellent addition to a cut flower garden as 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 whether your sunflowers are annual or perennial by looking at a few key traits, including their roots, seed heads, and stems. An annual plant has a single deep taproot, a main stem from which others descend, 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 the seeds to save them for the next year, or you can eat them. The flower is not coming back, so you should remove it from your garden. Cut off the faded flowers of perennials and dispose of them. You will likely see more sunflowers blooming this year and the plant will come back next year.
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