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growing sunflowers from seed

Sunflowers for Grownups: Growing Helianthus Annuus From Seed

Growing giant sunflowers, such as any of the Mammoth varieties, is the slow-motion equivalent of "Hold my this!" Unfortunately, most backyard gardeners who plant these spectacular sunflowers are too young to drink, and as they grow up, they dismiss sunflowers as novelty plants. We do agree that sunflowers are the perfect introduction to botany for little kids, but ankle-biters shouldn't be the only ones to experience the joy of growing Helianthus annuus.

Nor should you limit yourself to the sky-busting varieties! Choose from the various flower and petal textures, colors, sizes, and patterns to suit your personal aesthetic, or select a dual-purpose type that produces munchable seeds or food for songbirds. Sunflowers can grow as little as 12" high or to a dizzying 12' tall, and we carry a whole slew of options for these and everything in between.

Sunflower's rich cultural history

If you know about maize's cultural significance to native North Americans, you might be surprised to learn how equally important sunflower was to indigenous people living in the regions we now call northern Mexico, Arizona, Texas, and New Mexico. Many pre- and post- Columbian western cultures relied upon sunflowers as part of their diet. Sunflower seeds, like maize, were ground into flour or mush, with or without other seeds and berries. The heads were used to make red or purple dye or as ceremonial decorations. Sunflower oil served both culinary and cosmetic purposes, and the entire plant, when crushed and made into a poultice, was a popular treatment for snakebite. And, of course, the roasted seeds were (and still are) a favorite portable snack.

As early New World cultures began to grow their own staples, evidence of cultivated varieties began to spring up around the entire continent. Ethnobotanists tend to agree that wild sunflowers originated on the Colorado Plateau and that trading helped disperse the plants around North America where they became subject to domestication. According to Texas Beyond History, samples of cultivated varieties dating back 4265 years were found in eastern Tennessee in the mid-1990s. Seeds found more recently in Tabasco, Mexico, one-upped the previous discovery, dating their cultivated samples to 4130 years ago. We imagine there was some friendly competition between the archaeologists, especially given that the discoveries were published within five years of each other. Who has the oldest, mankiest seeds?

Seed heads of wild-form (pre-domesticated) sunflowers have been discovered at Hinds Cave at the Lower Pecos Canyonlands (Texas/Mexico border), where anthropologists estimate early Americans lived for approximately 9000 years—up until about 1000 years ago. It's up for debate whether the sunflower was domesticated before maize, which is believed to have been first domesticated more than 8,700 years ago in Mexico's Central Balsas River Valley.

To Russia (and back!), with love

According to the National Sunflower Association, Spanish explorers carried native-improved sunflower seeds to Europe in the 1500s, and there the plant became a popular ornamental. A 1716 English patent for a sunflower seed press indicates the Europeans finally caught on to the fact that the sunflower is more than just a pretty face, but it was Peter the Great who really pushed commercial sunflower oil production. During Lent, cooking oils were forbidden, but the Orthodox Church never specifically outlawed sunflower oil (did some sunflower farmer have dirt on the church?) and this aided the commodity's establishment in Russian food culture.

Russians began selecting for oil production and snackable size. The latter became known as the "Russian Mammoth" variety, and both were brought back to North America where they became the most popular commercial sunflower crops for livestock feed and human consumption. Nowadays, sunflower oil is such a hit in Europe, (especially due to concerns over "bad" cholesterols in animal fats) much of what's grown here in the U.S. and Canada are shipped out for production overseas.

Nomenclature and classification

Helios is Greek for "sun," and anthos means "flower." (Stop snickering; Annuus means "annual"). In spite of the enormous variance in colors, growth habits, and size, all sunflowers are in the same species (Helianthus annuus) and classified by variety.

Flowers and foliage

Helianthus annuus are members of the Asteraceae family, which include daisies, asters, and coneflowers. They're fast-growing annuals that tolerate a wide variety of environmental conditions and are so easy to grow, a toddler (or very buzzed home gardener, or a hoarding squirrel) can do it. Whether you select them for their color or their size, sunflowers are all drama...but the good kind of drama.

As of this date, we carry 28 individual sunflower varieties, plus our Crazy Sunflower Seed Collection and Double Dance Mix. If we were to describe each cultivar in this post, we'd all miss the growing season. As you browse through our catalog, keep in mind that there are varieties developed for the following:

  • Branching, compact growth with multiple flower heads
  • Tall, single-stemmed plants with single flower heads (typically those grown for their seeds)
  • Dwarf varieties
  • Pollen-free varieties
  • Single, double, or multiple-flowered (as in layers of petals)
  • Large vs. small central disc
  • Bi-coloration

As with all Asteraceae, the sunflower's heads are compound, meaning they're made of two sets of individual flowers. In the centers are the disc florets, and each petal is actually a ray floret. Sunflower leaves tend to be proportional to their flower heads, but in the grand scheme of things, they're still quite large whether you're looking at the smallest or the largest varieties. The typical leaf is round, triangular, or heart-shaped, with a rough, slightly crumpled texture. The stalks, especially those on the giant types, are hollow, turning brown close to harvest.

Sunflowers are late-season bloomers, usually firing up in early July and lasting through August. Colors include cream, yellow, gold, red, burgundy, and deep purple. Some varieties may produce different shades or colors from the same batch of seeds, and many are bi-colored.

Environmental preferences and uses

Where you grow them is up to your imagination, depending on your chosen sunflower variety and the following basic requirements. Use dwarf varieties as borders or container plants, and medium-sized, branching types with complementary-colored bedding specimens (blues, purples, and whites). Large sunflowers aren't subtle, and they look great paired with love-lies-bleeding; both plants have quite a bit of substance and together, they make quite a statement. Their foliage is similar in scale and shape, but love-lies-bleeding's crimson, cascading effect works very well with the upright, columnar sunflower.

Mid-sized sunflowers look great peeking over the tops of picket fences, and giant types can provide shade for tender veggies when summer grows hot. Slap some large googly-eyes on them and plant them along the fence between your yard and your neighbors', just to be obnoxious. Sunflowers tend to orient their heads to face south (here in the Northern Hemisphere) so keep that in mind when you pick out your planting area.

Most sunflowers attract beneficial insects, and the seed-bearing types draw in all sorts of birds. Vegetable and fruit growers like to distract avian pests from their crops by planting sunflowers well away from their valuable plants. Whether this works on a backyard scale (if it works it all) is up in the air, but it's always worth a shot.

Sunlight: As their name implies, sunflowers require full sun. Aside from that, they're adaptable to a wide range of conditions, provided that taller species are protected from strong wind. Their annuals are reliable in USDA Hardiness Zones 2 through 11.

Water: Sunflowers do well in low-to-medium irrigation areas, but should receive consistent moisture during the germination and establishment phase. If you notice excessive wilting in the leaves, level up your watering game. You'll be surprised, though, how well they do when you neglect them. Drier soil tends to be more supportive of sunflower's flimsy roots.

Soil: Sunflowers prefer poor-to-medium soil. Nitrogen is good for giving them a head start, but too much will cause them to tip over (lodge). We suggest amending the soil with well-aged compost to improve drainage and provide the bare necessities and leaving it at that. This should provide them with the right nutrients to get them through their flowering phase. Sunflowers appreciate soil pH between 6.0 and 7.5; in other words, aim for neutral, but don't lose sleep over a bit of variance.

Sunflower care, maintenance, and harvesting

Sunflowers grown in high-nitrogen beds, or windy, unprotected areas, may require support via staking. Keep an eye out for powdery mildew, fungal spots, and rust. Bugs that like to munch on leaves might make a dent in the foliage, so beware of beetles and caterpillars. Rodents and birds might show up to feast on dropped seeds or those still on the heads. So, if you want to keep a sunflower seed crop for yourself, be prepared to protect the heads with a fine mesh cloth (cheesecloth works well) or a large paper bag while they're drying on the stalk, or hanging upside-down in a well-ventilated dry area. Leave about a foot of the stalk for ease of handling.

As with all annuals, you'll want to decide whether you'll allow your sunflowers to reseed themselves. If you do, you'll have lots of volunteers the following spring, though they won't necessarily grow true to their parent plant. Fortunately, unwanted sunflower shoots are easy to recognize and remove.

It's important to wait until the seed heads have faded from green to yellow, the petals have dried and begun to fall off, and the backs have turned to a dry brown. Around this time, the seeds will begin to loosen, and you can use your fingertips or the palm of your hand to "scrub" them into a large container. (Pssst...use child labor!) We use household storage tubs, and then transfer them to paper sacks before stashing them in a cool, dry, dark area. If it's been humid or rainy recently, be sure to dry them for a while longer on a mesh screen in a warm, arid room.

If your goal is to stock up on snacks, we suggest you roast the seeds as soon as they're dry. The University of Illinois agricultural extension has a fantastic recipe for preparing and roasting sunflower seeds, and additional harvesting tips.

Growing sunflowers from seed

If food-caching squirrels can inadvertently grow sunflowers, so can you! The following are general guidelines for growing sunflowers from seed. Refer to your seed packet for specific instructions.

  • Seed Treatment: None required.
  • When to Plant Outdoors: After last spring frost.
  • When to Plant Indoors: 4 weeks before spring frost; keep seedlings in a warm, sunny window.
  • Seed Depth: Twice the width of the seed. Sunflowers don't need sunlight to germinate.
  • Seed Spacing: 12" for smaller varieties, 2' to 3' for larger.
  • Days to Germination: 7 to 14 days at 70°F.
  • Transplanting Tips: Plant seedlings outdoors when they're 4" to 6" tall.

Indoor sowing is kind of pointless given the speed by which these suckers grow, but they're a fun project for small children. Does anyone remember taking home from kindergarten that seedling in a paper cup? We do. Sunflowers are the gateway plant, sparking curiosity about the natural world.

A vibrant garden starts with Seed Needs

Our sunflower seeds are heirloom varieties developed through open pollination or good-old hybridization by way of crossbreeding. We stock fresh, hearty sunflower seeds with enough stored energy to allow your plants to rocket skyward and thrive.

Unlike squirrels, we don't stockpile our seeds. We only keep on hand what we can expect to sell in any given season, so we can ensure that our customers get the highest possible germination rates. So when we're out of stock, that's usually it for the season! Contact us if you want dibs on your preferred sunflower varieties, or if you've found an obscure variety you'd like to us to add to our catalog. If we can find a reliable, reputable supplier, we'll see what we can do!
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