Black Oil sunflower: An heirloom variety with high-quality seeds

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If you’re interested in black oil sunflowers, you’re not alone! There is so much to learn and enjoy about these flowers. They have many purposes such as nourishing the soil and providing nutrient-rich food for song birds.

Black Oil Sunflowers are an heirloom cultivar known for their high-quality seeds that are used for oil and bird feed. These sunflowers bloom during the summer months and stay for three weeks. For planting, use loam soil, give the plant one inch of water per week, and place the plant in direct sunlight. Black Oil Sunflowers are easy to grow and perfect for pollinator and wildlife gardens.

Black oil sunflowers are popular worldwide. This is because they are so easy to grow and they can withstand nearly any growing condition. These durable sunflowers impress many with their height and large size. Keep reading below to discover everything you could want to know about black oil sunflowers.

Black oil sunflowers
Black oil sunflowers

Black Oil sunflower: The basics


Black oil sunflowers look just like any other classic sunflower. They have bright yellow petals that surround a brown center.

The difference in color is their seed. Most sunflower seeds are brown/grey (and sometimes striped). However, black oil sunflower seeds are coal black. There is a striking color contrast between the petals and the seeds in the mature flowers.


The size of the black oil sunflower is impressive, as it is able to reach an average of eight feet in height. They are large in size, as the average sunflower reaches three feet in height. Black oil sunflowers can reach up to ten feet, meaning some are more than three times larger than other varieties.

One flower or branching

Black oil sunflowers produce one flower, meaning they are not branching. They only produce one, beautiful flower per stalk. The flower itself is usually about twelve inches across.

Are the seeds edible?

One of the largest reasons black oil sunflowers are well known is because of their seeds. These seeds have a large amount of oil in them, especially compared to other sunflower seeds. They have. a high concentration of oil and also provide ample amounts of protein.

While black oil sunflower seeds are edible, you will want to wash them first. These seeds are not commonly used for human consumption so they are not typically packaged in a way that is safe for people to eat.

Black oil sunflower seeds
Black oil sunflower seeds
Black oil sunflower seeds - bird seed for feeding song birds

Reasons to grow Black Oil sunflowers

There are two main reasons to grow Black Oil Sunflowers. These reasons are to purify the soil and to have access to their seeds. Black Oil Sunflowers are able to improve the environment around them, which is why many choose to grow this variety of sunflowers.

Black Oil Sunflower plants are often planted to purify the soil. These sunflowers dig their roots deep into the ground. They are able to pull nutrients and soil contaminants toward the surface, creating a better-growing environment for everything around them.

The second reason to grow Black Oil Sunflowers is for their seeds. These seeds are commonly used to feed wild birds and to feed backyard chickens, as they provide lots of valuable nutrients. They can improve the health of songbirds and your poultry as they are high in protein and have been shown to increase weight.

Black oil sunflower seeds for birds at garden center
Black oil sunflowers - sunflower oil
Planting black oil sunflower
Planting black oil sunflower

How to plant Black Oil sunflowers?

Here are the basics of planting Black Oil Sunflowers.


Using the correct soil is one of the most important parts of planting sunflowers. For Black Oil Sunflowers, you will want to use loam soil. Loam soil is a combination of sand, silt, and clay. This soil is great for retaining water while still providing a good amount of drainage. Drainage is vital for sunflowers because they cannot handle too much water. That said, Black Oil Sunflowers are very tolerant of less-than-perfect soil. Try planting them in nutrient-poor soil, and they just might grow anyway!


Black Oil Sunflowers do not need a lot of water from their gardeners. In fact, they only need one inch of water per week. If you live in a rainy area, then you will likely not have to water them at all and can just let nature take care of it. However, if you live in an area that is particularly hot, then more water may be required. While they are drought-tolerant, they do grow best when they aren’t limited by lack of water.


Black Oil Sunflowers need full sun. They need at least six hours a day in direct sunlight to reach their full potential. If you live in an area that does not have enough light, then artificial lights may be necessary. These lights will replicate the sun as closely as possible, but direct sunlight is still the ideal option.

Black Oil Sunflowers need a minimum of six hours of sunlight a day. They do better if they receive more than this though, as this will help them to be the best that they can be. It’s right in the name; these blooms love the sun!

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Questions about growing Black Oil sunflowers

How fast does the sunflower grow?

Black oil sunflowers need over three months to reach full maturity. It is not until after over one hundred days that they are fully grown. After about 110 days, you can assume that they are not going to grow any larger.

Does it bloom more than once?

Black oil sunflowers do not bloom more than once. They can bloom one time during late summer or early fall. They commonly bloom during the summer months, however, and then last for another three weeks.

Once they bloom, relish in the moment. These sunflowers are stunning to look at and nothing else will compare.

Do they come back every year?

Black oil sunflowers do not come back every year. In order to get black oil sunflowers every year, you will have to replant them.

Black oil sunflower
Black oil sunflower
Mary Jane Duford
Mary Jane Duford

Mary Jane Duford is a gardening expert and founder of Home for the Harvest. She's also a professional engineer, certified permaculture garden designer, and master gardener in training. Mary Jane has been featured by publications such as Real Simple, Mother Earth News, Homes & Gardens, Heirloom Gardener, and Family Handyman.