Mammoth sunflowers are bright yellow in color. Their striking golden petals surround a brown center. Their color is similar to that of other sunflowers as they have the classic sunflower look.

Mammoth sunflowers originated in North America and were cultivated by Native Americans. However, in the eighteenth century, Eastern Europe made this plant even more popular. Mammoth sunflowers were used during this time period to meet the rising demand for sunflower seed oil. They are still currently used for their oil because they produce much more of it than most other sunflower varieties.

Once the seedlings are established, Mammoth Sunflowers do not need a large amount of water to reach their full potential. Some gardeners do not water their sunflowers at all, letting them live off the natural precipitation and groundwater. To reach giant heights, however, these plants generally do require added water. While they are drought-tolerant, their impressive height can be stunted by lack of water, especially in the first few months of life. Unless conditions are overly dry, they only need one inch of water per week. If the area you live in receives a lot of rainfall, then you may not need to water your sunflowers at all.

Apart from their enormous beauty, the Russian Mammoth Sunflowers are practical additions to most homesteads. In fact, they can produce over one thousand seeds per head, making them a great supplement for your backyard flock!

A Russian mammoth sunflower is visually stunning not just for its size (they get to be about 8-10 feet and their head diameter can be easily over 12 inches), but because of its bright, happy color and large, umbrella-like leaves. The stalks are a good 3-4 inches in diameter when the soil is good and then you have to saw them down at the end of their season. This however is great for making kindling sticks, because they burn fast and hot when dried. Sometimes the heads get so huge that the stalk begins to bend but most often they grow up near perfectly straight and tall and can be cut down into orderly shapes for your kindling pile desire. Or you can always compost them!

This sunflower only produces one flower during its lifespan. These sunflowers will bloom during late summer or early fall. After they bloom, the flower will last a maximum of three weeks. The flower will then droop over, petals will curl, and the flower head will become a target for hungry birds that would like to eat the sunflower seeds. The mammoth sunflower does not bloom more than once.

Russian Mammoth Sunflowers are also deer resistant and perfect for cottage or cutting gardens. They are best planted in a somewhat sheltered location where they won’t get too much wind, but your soil doesn’t need to be exceptional in order to grow these annuals.

When To Plant Mammoth Sunflower Seeds

Mammoth Sunflower seeds tend to grow best when planted soon after the last frost date in your local area. You can certainly plant them before the last frost date, but beware that the tender seedlings may be damaged by cold temperatures. You can also plant them in early summer (typically into mid-July), but beware that temperatures may cool in the fall before the plants can reach their ultimate mature height.

Harvesting Mammoth Sunflower Seeds

Either raw or roasted, sunflower seeds make a delicious, healthy snack. You can also preserve the seeds for next year’s planting, or use dried seeds as bird feed. When the flower head wilts and the foliage turns yellow, the sunflower is ready for harvest.

1. Cover the flower head with cheesecloth to allow it to dry on the stem. The cheesecloth will protect the seeds from hungry birds, squirrels, mice, and deer and catch any loosely falling seeds as they dry.
2. Cut the dried flower head from the stem.

To dry the heads indoors, wait until the sunflower head is maturing but the back is still yellow. Cut the stalk off about 6 inches below the head of the flower. The seeds on the outside should be ready to harvest while the inner seeds should not quite be ready yet. Hang each head upside down in a warm and well-ventilated area to let the seeds dry and mature.

The sunflower seeds can be harvested once the head is completely dry. Put a bucket under the head to catch the seeds. Use gardening gloves as the seed head can be somewhat sticky. Then rub the sunflower head so the seeds pop out and fall into the bucket. The seeds can be rinsed with fresh clean water and set out to dry, or coated in a bit of oil and roasted.