By Yvonne Lopez, Bexar County Master Gardener Intern
July 2023
Looking for some color for your garden this summer? Bright sunflowers (Helianthus) can be a beautiful addition to your garden for many reasons.
- Often, people think of yellow and orange sunflowers, but they bloom in the most stunning colors. I especially love the red and chocolate colors;
- They vary in height, adding depth and diversity to your garden. Some varieties can grow from 1.5 feet to 10 feet high;
- These beauties attract lots of pollinators;
- Most sunflowers can withstand the Texas heat since they require full sun; and,
- Sunflower seeds may be eaten, used as an ingredient in cooking, and make gorgeous flower arrangements.
Factors to Consider When Growing Sunflowers
There are so many varieties of sunflowers: selecting the right variety for your garden is a key consideration. The sunflower packets I have purchased are annuals, but you can find perennial sunflowers as well. Those that are seedless are often referred to as pollenless sunflowers, and are often used for the cut flower industry.
You can purchase sunflower packets just about anywhere, but if you’re looking for a specific variety you may want to look at a local nursery or a specialty store, including online retailers. Because I just love all the colors, the most difficult part about selecting sunflowers is deciding on a few seed packets/varieties and keeping myself from purchasing all the packets on the shelf!
Space availability in your garden is a key factor to consider before purchasing your sunflowers. If you have limited space, then you may find smaller varieties more suitable. For those who have plenty of room, you have the opportunity to plant larger varieties and can see these beauties reach heights ranging up to 10 feet tall.
For the taller varieties, you may want to consider staking them or using a trellis for support. I learned the hard way that some of our high winds will take down sunflowers in a single evening of strong gusts.
Sunlight is critical for sunflower growth, so make sure these vibrant flowers are planted in an area where they will receive at least 6-8 hours of sun.
If planting sunflowers from seed, always plant after the danger of frost has passed. You can start your seeds indoors or outdoors. Ultimately, it comes down to when you want to see your blooms. I’ve read that planting can be anytime from March to as late as August depending on your zone. I recently planted sunflowers and hope to see blooms sometime in August or September. It is useful to follow the planting guidelines on the seed packet, which provides spacing and depth recommendations. Sunflowers typically take 10-13 weeks to grow and here in San Antonio at this time of year, you may see wild sunflowers blooming along greenbelts and roadways.
Sunflowers are fairly easy to grow and maintain but they do require some care for ideal growth and blooming. I haven’t used specialized fertilizer: in the past I have used standard plant food and they have performed very well. You do want to be sure to water regularly. Right now, we are experiencing sizzling temperatures so make sure your sunflowers are getting the water they need. The soil should be consistently moist, never soggy, and not too dry.
When watering, be sure to water at the base of the flower and not overhead, which can lead to disease, including rust, powdery mildew, southern blight, and cotton root rot. You may also find aphids, sunflower moths, caterpillars, and weevils, all of which can wreak havoc on your sunflowers. A call into the BCMG hotline or a visit to your local nursery can help manage these types of disease and/or pests.
Wildlife may also present another challenge: If you have deer, you may want to consider fencing and/or netting covers for the heads of the flower to help keep birds and squirrels at bay.
Harvesting your sunflowers will depend upon the variety. Most sunflowers can be cut and used for a simple bouquet or floral arrangement. When harvesting the seeds, I usually wait until the flower has dried up, the petals begin to fall, the back of the head of the flower turns brown and the seeds themselves are black with white stripes, depending upon the variety.
If you are looking for color or want to attract pollinators, consider making sunflowers a part of your garden landscape.
Photos by author