Nothing announces the arrival of summer like a bed of vibrant sunflowers. This North American native is a beautiful addition to flower and vegetable gardens and is extremely easy to plant and grow. Measuring up to 12 feet tall, these flowers come in several colors (not just yellow) and grow in a wide range of hardiness zones.
It’s best to plant sunflowers in late spring. Plant the seeds in neutral, well-drained soil, space them six inches apart, and place them in a spot that receives six to eight hours of sunlight daily. Water them thoroughly and thin the seedlings when the first set of leaves appears.
Sunflowers add beauty and color to your garden, provide food for squirrels and birds, and brighten your floral arrangements. Most types also have beautiful blooms, which you can harvest for seeds or use to make rich sunflower oil. Let’s look at how to plant sunflower seeds, when to start the planting process, and whether the climate affects their growth before moving on to the different types you can choose.
How to Plant Sunflower Seeds
It’s straightforward to plant sunflower seeds (on Amazon). You just need to choose the right spot, prepare the soil, place the seeds into the ground, and give them the strongest possible start. Here’s a more in-depth look at how to plant sunflower seeds:
Prepare the Soil
Sunflowers thrive in well-draining soil. If you have heavy soil, add around four inches of compost. Mix a few nutrients into the top six inches of the garden bed and fertilize the soil before planting.
It’s ideal for growing sunflowers in slightly acidic soil with a pH between 6 and 7.5. If you don’t know your soil’s pH level, simply conduct a home soil test and adjust the pH level accordingly.
Plant the Seeds
Different sunflowers need different spacing and planting depths. So, how deep you need to plant your seed ultimately depends on your seed type.
Generally, you should plant sunflower seeds at least half-an-inch deep and space them around six inches apart. If you’re growing your sunflowers in rows, leave about two to three feet of space between each row. If the soil temperatures are just right, you’ll see seedlings sprouting up in just 10 to 14 days.
Keep in mind that you need a lot of space to grow sunflowers. If you’re growing them indoors, place three seeds into a three- to four-inch peat pot. You can also plant the seeds after every few weeks and enjoy continuous sunflower blooms throughout the summer.
Give Plenty of Water
Sunflower seeds contain a lot of natural oil, so they need large amounts of water for proper germination. Ensure you water the soil thoroughly after planting and keep it moist with light; frequent watering until the seeds germinate.
If you’ve planted your sunflowers indoors, it’s better to cover the pots with a clear plastic wrap to prevent moisture from escaping. Remember to remove the plastic once the seeds sprout.
Thin the Seedlings
Once your seedlings produce their first set of leaves, thin them according to their recommended row spacing. For example, smaller sunflowers usually need around six inches of space between each plant, while larger varieties might require up to three feet.
While you can space your sunflowers closer for a more vibrant garden aesthetic, keep in mind that crowded plants usually produce smaller flowers.
When planting indoors, reduce the seedlings to only one seedling per cup. Then, just pick the strongest flower and thin back the others.
Choosing the Best Planting Spot
It goes without saying that sunflowers thrive in the sun. They’re full sun plants, so choose a planting spot that receives six to eight hours of direct sunlight daily.
Sunflowers are also extremely hardy and can survive extreme heat. However, it’s ideal to grow them in temperatures between 70oF and 78oF and sow them in soil with a temperature of at least 55oF to 60oF.
These flowers love neutral soils, but you can also grow them in slightly alkaline or slightly acidic soils. It’s better to plant them in soil with a pH level somewhere between 6 and 7.5.
While sunflowers are heavy feeders, ensure you don’t over-fertilize your plants, as it can lead to weak stems. For best results, add a slow-release fertilizer to the soil before you plant the seeds.
It’s also important to consider what you’ll plant near or around your sunflowers. For example, some types grow incredibly tall and might block the sunlight of other plants, so avoid planting them with dwarf flowers. On the other hand, their short growing season (70 – 100 days) means that you can plant them in most gardening zones.
What Time of Year is Best for Sunflowers?
It’s best to plant sunflower seeds in late spring when the soil is nice and warm. Most seeds germinate when the ground reaches a temperature of 70oF to 85oF, so make sure you plant your sunflowers right before the soil reaches this point.
This usually translates to a ground temperature of between 60oF and 70oF. However, if you don’t know your soil’s temperature, just plant your sunflowers around three weeks after the last hard frost.
In order to get a headstart on the growing season, you can plant your sunflowers indoors. Simply place the seeds into pots after the last spring frost, and transplant them once the soil reaches the right temperature.
Does Climate Affect Sunflower Growth?
Climate does not affect sunflower growth, so you can have a stunning sunflower bed no matter which state you live in. The flowers thrive in all 50 states of the US, with most varieties blooming in the summer. Their native range extends to Northern Mexico, Central America, and Canada.
Their native environment is dry, open spaces, like plains, meadows, and prairie lands. However, sunflowers also occasionally grow like weeds in pastures and farm fields. In these terrains, they share their space with other prairie grasses, wildflowers, rodents, snakes, and many different types of insects.
Sunflowers can also withstand long periods of drought and intense heat. However, to ensure bigger, healthier flowers, it’s important to give your sunflowers supplemental water during extended periods without rain.
It’s important to note that sunflowers can also tolerate wet, humid weather. However, well-draining containers or soil are essential for healthy growth in such climates.
What Are the Different Types of Sunflowers?
Despite what most people believe, not all sunflowers have the same color and size. There are several different species of sunflowers, but to make things easier, we’ve broken them down into three groups:
Because of their rough and tall stems, sunflowers grow several feet tall. Reaching heights of up to 16 feet, these enormous blooms are always trying to get their bright petals as close to the sun as possible.
Tall sunflowers usually feature large, single stalks with big brown centers and vibrant, golden-yellow petals. Their height and ability to grow countless seeds make them a favorite among birds as well.
However, the larger the flower, the larger the responsibility, so keep in mind that you’ll have to give a lot of time and effort to your sunflower if you want it to grow to its maximum height.
Here are a few of the most popular tall flowers you can grow in your garden:
- American Giant
- Sunforest Mix
- Schweinitz’s Sunflower
- Russian Mammoth
Most people consider sunflowers extremely tall plants unsuitable for home gardens. However, due to their increased hybridizing, there is now a wide range of sunflowers that only grow up to three feet tall.
Dwarf sunflowers love to grow in clusters and take very little space in your planters and gardens. They’re also extremely low-maintenance and thrive in full sunlight. Because of their small stalks, you’ll only need to space their seeds three to six inches apart.
Some of the most popular dwarf sunflowers include:
- Sundance Kid
- Little Becka
- Sunny Smile
- Suntastic Yellow
Due to hybridizing, sunflowers now come in a wide range of colors as well. You can mix and match several different types and add a burst of color to your patio, dining room table, or garden.
From deep red wine to light, creamy custard, here are a few of the most popular colored sunflowers:
- Ms. Mars
- Moulin Rouge
Which Type of Sunflower Should You Grow?
With such a wide variety of sunflowers available today, choosing the right one for your garden can be incredibly difficult. From growing bird seeds to creating centerpieces and attracting pollinators, each type answers a different gardening need.
Multi-bloom sunflowers branch out in several hues, making them ideal for borders and flower beds. From heirloom favorites to the latest hybrids, here are some of the most popular branching sunflowers you can grow in your garden:
If you love variety, then Autumn Beauty is definitely the way to go. This open-pollinated flower grows up to 80 inches tall and boasts vibrant fall-hued blooms, including reds, yellows, and oranges.
This hardy branching type grows up to 60 inches tall and produces lovely, four-inch, creamy flowers with dark centers. But, like most old-fashioned varieties, they take a long time to grow and bloom after 90 to 110 days.
If you prefer growing sunflowers in containers and pots or want a more manageable and smaller flower bed, then dwarf sunflowers are your best option.
Some types grow large flower heads and reach a height of 36 inches, while some only produce delicate petite blooms. Here are a few of the best ones:
With bright yellow, double-petaled flowers, Teddy Bear can be described as fuzzy and cuddly. They reach two to four feet and produce blooms up to six inches wide. They take around 75 days to bloom, but their flowering spree lasts approximately five weeks.
This tiny plant produces enormous flower heads on stalks that grow 18 to 24 inches tall. It attracts bees and several other pollinators and is edible as long as you grow it without any chemical sprays.
While sunspots are ideal for growing in containers, you can also plant them in a low-lying flowering hedge along walkways. They look great in front of taller flowers with contrasting colors, such as ‘Velvet Queen,’ as well.
All open-pollinated sunflower types have edible seeds, but some garden cultivars are especially popular because they produce large amounts of healthy, meaty seeds.
Some of these flowers are stunning heirlooms that tower over all other plants and produce flower heads that measure more than a foot in diameter. Meanwhile, some are more vibrant and recently-bred cultivars.
If you love the taste of sunflower seeds, here are a few types you can plant:
Mammoth Gray Stripe
One small Mammoth Gray Stripe seed can grow a stalk up to 12 feet tall. The flower head measures at least 10 inches wide and might even grow up to 13 inches in diameter.
This flower is open-pollinated, so it will attract bees and several other pollinators to your garden. However, it’s important to note that it takes a very long time to grow. Once you sow the seed, it will take around 100 to 110 days for the flower to bloom fully.
The blooms usually last for a month before they start to droop in the harvesting season. If grown in the right conditions, each flower has the potential to produce more than 100 seeds!
If you don’t want large sunflower stalks dominating your garden but still want to enjoy homegrown sunflower seeds after the blooming season, then snacker may be the flower for you.
This popular hybrid grows up to seven feet tall and blooms after 60 to 70 days. Each flower holds up to a pound of delicious, meaty seeds, which become ready to eat about six weeks after blooming.
If you don’t want gigantic, contest-sized sunflowers, you can opt for more medium-statured types. In fact, it’s not necessary to grow a 15-foot enormous sunflower just to add a bit of height to your borders, hedges, or fences. Sometimes, varieties that reach four to seven feet do the job just as well.
Medium-tall sunflowers look best in full meadows and long rows of single-stem flowers. They’re lovely additions to striking floral arrangements and make excellent centerpieces.
Here are a few of the most vibrant moderately tall sunflowers:
Extremely easy to grow and a favorite among pollinators, Lemon Queen grows five to seven feet tall. As the name suggests, it produces lemon-colored blooms with deep brown centers.
The plant takes around 100 days to mature, so patience is essential. However, since the buds are edible, you can also harvest them a bit early.
Taiyo takes around 14 weeks to bloom, an extremely popular heirloom sunflower from Japan. Each plant only produces one flower head that measures about 10 inches in diameter.
It also attracts butterflies and bees and produces dainty petals with deep mahogany and orange centers. However, remember that these statuesque stunners throw a lot of shade, so be careful when choosing their companion plants.