As they get taller, your Mongolian Giant sunflowers may be at risk of toppling either from wind or the weight of the flower head. Add stakes as needed or tie them to posts with gardening twine if you’ve planted them along a fence. When growing giant sunflowers it’s important to choose the right varieties for your purposes. The world’s tallest sunflower measured 9.17m (30 feet, 1 inch) and was grown in 2014 in Germany by veteran record holder Hans-Peter Schiffer of Germany. This world record sunflower was the product of years of plant selection and seed saving, as well as ideal growing conditions that year. But while it may take you a few years to win the world record, starting at the local competition might be entirely within your reach. Open Pollinated varieties

To sow your sunflowers, simply press your seeds about one inch into the ground and about 6 to 8 inches apart (if you’re planning on thinning them, more on this below) or about 20 inches apart if you’re not oversowing.Watch your sunflowers bloom in late summer and take note of the many beneficial pollinators and other creatures that visit them. Bees, butterflies, and more wildlife are attracted to the bright yellow petals and brown centers full of pollen.

And while I leave a lot of other seed-producing plants in the garden to feed the local bird population, I readily admit that I’m not as generous with my sunflower seeds. This is a unique variety of giant sunflower that produces stunning, bi-colored blooms. It can grow up to 8-10 feet tall and produce heads that are up to 10 inches wide. Find Are Sunflower Perennials here 12. Sunzilla Sunflower It’s easy to over-do fertilizer, hurting both the plant and the soil so follow the instructions on any product you use. More is not more with plants: they can only absorb what they need when they need it under the right conditions and surplus can harm the environment. 11 WaterIn addition to the native sunflowers that reseed themselves every year I think I’ll plant a few Mongolian Giants each summer. If you’ve got a favorite sunflower variety, either ornamental or edible, please leave a comment.

The Russian giant sunflower is one of the most popular varieties of giant sunflowers out there. It can grow up to 12-15 feet tall and produce heads that are over 1 foot wide! 3. Giant Yellow The Titan Sunflower is an heirloom tall sunflower variety that remains one of the tallest sunflowers available. Selected from the Mammoth Sunflower (described above), the Titan is well-suited to home gardens as it has a sturdy root system and rarely needs staking. Germination may be slow and erratic. A fluctuating temperature of 75°F during the day and 50°F at night may help.Even among these, there are many, many varieties and a huge range of heights and sizes, colors and forms available. Skyscraper Sunflower Sunflowers are pretty big compared to most flowers, but there’s one behemoth relative of the sunflowers we all know and love. Note: For those varieties that indicate a (1) or (6), a very light covering of vermiculite will allow adequate light to the seed and keep it uniformly moist.