Sunflowers (Helianthus annus) are usually associated with vast fields of giant yellow flowers that face the sun.
Unfortunately, not all of us are close enough to a field of sunflowers to enjoy its beauty. But that shouldn’t stop you from enjoying it in your own garden.
Although native to North America, these flowers are loved around the world for their culinary uses. Sunflower was a central food crop for early Indigenous peoples and remains vital today in the production of oil and sunflower seeds, a favorite snack for humans and birds.
In your garden, sunflowers can literally stand out from the rest of the flowers in your garden. These plants are known for their impressive height, with the tallest ever reaching 30 feet in height. There are also smaller varieties for gardeners who don’t want to break records quickly.
Cultivating these towering treasures isn’t difficult either: they largely manage on their own. Here’s how to start.
When and where to plant
Sunflowers (unsurprisingly given their name) need a sunny location with at least 6-8 hours of sunlight per day. For planting, use well-drained soil enriched with organic matter or a slow-release fertilizer.
There should be enough room for the long taproot to grow downward. If you are growing in containers, choose one of the dwarf varieties and plant it in a deep pot to allow plenty of room for the roots. If you choose one of the taller varieties, plant in a spot protected from strong winds to prevent the plant from toppling over.
Start seeds in the spring after all danger of frost has passed. The soil should be warm enough to facilitate germination. In most areas, you can plant sunflowers from mid-March through May.
Plant the seeds 1 inch deep and 6 inches apart. On taller varieties, space the seeds further apart to ensure the flowers reach their full size. You can also plant the seeds closer together and thin out weak, overly dense seeds once the plants are a few inches tall.
Stagger your plantings for continuous flowering. Leave room for new seeds after your first planting and replant every 2 weeks. Depending on the variety, your flowers will be ready in 80 to 120 days.
You can also sow sunflower seeds indoors to boost your growing season.
Water well after planting. The seeds should germinate in about 7-10 days. After planting, keep birds away from the site until the plants are established. They love seeds as much as humans and will certainly dig if given the chance.
Sunflowers tolerate a variety of conditions. They’re not particularly finicky – a fair amount of sun is all they really need to thrive. To get the most out of your plants, they might need a little more care in these areas:
As mentioned above, plants need at least 6 hours of sunlight per day. Sunflowers are heliotropes (the heads face the sun), so they need lots of sunlight on all parts of the plant to stay upright.
Sunflowers can handle a lack of water, but they grow best when watered regularly. Water when the topsoil is dry and never allow the plant to sit in soggy soil. The flowers will let you know when they aren’t getting enough water due to their droopy crowns and weak stems.
Sunflowers can withstand high temperatures and a bit of cold for short periods of time, as long as they are controlled and their other needs are met.
Sunflowers do not need frequent fertilizing when planted in good soil. If the plants need a boost to thrive, use a fertilizer high in phosphorus and potassium to encourage flowering.
Taller sunflower varieties need support as they grow to prevent them from toppling over. Place a stake next to the plant and tie the stem to the stake as the plant grows.
plagues and diseases
Sunflowers generally do not have problems with common garden pests and diseases. Mold can affect the plant, but it can be killed with a general purpose fungicide. You can also come into contact with the sunflower moth, which can be killed by hand or with a pesticide.
Your main concern will be the large wildlife in the area. Sunflowers will attract birds and squirrels interested in the seeds. Deer are also known to bite into the flower heads of the plant. If you have any of these problems, protect your flowers with a fence and netting around the plants.
Start cutting flowers for indoor displays early in the morning to avoid wilting. Carefully cut the flowers off the main stem and place them in a tall vase to support the weight of the head. Change the water daily and the flowers will last about 7 days before needing to be replaced.
Besides easy access to a bouquet of fresh flowers throughout the season, collecting seeds is the best part of harvesting sunflowers. Eat them as a snack, place them on a plate to crisp them up, or save them to plant next year.
To collect the seeds, allow the flower to dry out until the petals die back and the back of the head turns brown. The seeds should appear loose and easy to remove. You can also cut the stems early and let the buds dry out in a sunny spot away from birds.
When you’re ready to harvest the seeds, simply rub the head of the plant to release them. Rinse them to eat them or store them in an airtight container in a dry place to replant them.
That’s all there is. You don’t have to plant huge fields or own a farm, you can enjoy sunflowers in your own backyard. They produce so many seeds for the next season that you only need one to start. Once you’ve grown them, you’ll probably still want hundreds of these famous flowers.