Sunflowers are some of the most striking annuals. With stalks that range from “medium tall” to “extremely tall” and large, striking blooms, sunflowers provide a striking feature that recalls both a more rustic vibe and colorful wildflower gardening. Sunflowers come in a dazzling variety of colors and sizes, which means that you can create a unique color palette in your garden space. For the small-space or patio gardeners among us, many varietals of sunflower can be grown in containers. So let’s dig in and learn about growing sunflowers in your garden!
What are Sunflowers, Exactly?
Sunflowers are one of those plants that everyone knows about but many of us don’t know too much about. The most popular type of sunflower is common sunflower (Helianthus annuus). A native of North America, the common sunflower was originally cultivated by the indigenous peoples of the continent both as a food crop and as a decorative/symbolic plant. Sunflower are members of the daisy family (Asteraceae), and their name in English (and several other languages) comes from both their large sun-like inflorescence and its heliotropic behavior. Technically a cluster of smaller flowers (hence the many, many seeds) young sunflower heads follow the sun over the course of the day. Called “heliotropism”, the inflorescence faces east at the start of the day and turns with the sun, tracking westward across the sky and turning back east overnight. Heliotropism in sunflowers is restricted to younger plants, with mature inflorescences facing east full time.
As a cultivated plant, sunflowers have a wide variety of uses. The seeds are grown and used as food for both humans and animals or they are pressed to make an oil that can be used for cooking, as an ingredient in food, or for industrial applications. The Native Americans who originally domesticated the sunflower often grew them as part of their “three sisters” agricultural system and sunflowers still appear that way in some cases. Sunflowers are popular with pollinators, who thrive on the large amount of pollen produced by the inflorescence.
Please note that some varietals of sunflower have been bred to be “pollenless” or “pollen-free” in order to better serve as ornamental flowers. We recommend avoiding these in outdoor gardens in order to help support pollinators and a healthier natural environment
How to Grow Sunflowers at Home
Sunflowers are popular with home gardeners—particularly newcomers or younger gardeners—because they are fairly easy to grow. The large seeds make planting easy and the sunflower tolerates a wide variety of soil conditions. As the name might suggest, this plant does want full sun. They prefer sandy loam soils with good drainage, but will do well in clay loam or silty clay soils as well. They do like a slightly acidic soil pH, so a bit of soil testing and amendment may be in order.
Spacing for sunflower planting depends on the height of the mature plant. For plants that are 2 to 5 feet tall, six inches between plants should be sufficient. Sunflower varietals that reach a mature height of 5-8 feet will benefit from 12 inches of space, and the “giant” varietals that can reach up to 20 feet tall will need at least 24 inches between plants. If you’re planting in containers, plan accordingly to give individual plants enough space and ensure that the container selected offers good drainage and root management.
If you’re starting sunflowers indoors and transplanting later, we do recommend using a biodegradable seedling pot that can be planted directly without disturbing the roots of the young plant. Sunflowers tolerate a lot, but their roots are relatively sensitive so be aware of that while weeding. We would classify sunflowers as ‘medium’ feeders, meaning that they’ll need compost or fertilizer roughly every two weeks through their growing season. And while they do tolerate drought, keeping them well watered but not waterlogged will help ensure the biggest and best blossoms.
Sunflowers are proof that gardening is for everyone! By picking the right varietal, you’ll get a beautiful plant that will work in most garden spaces and is fairly easy to grow. We love sunflowers and we love talking about them so if you have questions or stories to share please get in touch!
Leave a comment