Nothing compares to the massive seed production of the giant, or Siberian, or striped sunflower. The sunflower is a compound flower, so each flowerlet becomes a seed, and the pollen is so attractive to bees.
The seed-head is white at first, as the flowerlets fall off, then takes on the swirls of grey as the seeds become mature. Squirrels and birds love the seeds, but squirrels will even eat the flower. The seedhead has a musty, sweet odor.
The plant easily grows to 10 feet with broad leaves, so it makes a great screen. We are backing up our bamboo fencing with the sunflowers and backing up that row with Butterfly bushes. If the sunflower seeds are bought by the pound instead of packet, the screen can be thick.
The stalks are thick enough to saw down when they are done. I leave them up for bird perches in the winter. Birds love to rest on relatively low vegetation to preen and watch for food.
Sunflowers also benefit the soil it has penetrated with deep taproots by slowly rotting the roots over the winter.
Sunflowers, pumpkins, and corn are heavy feeders, because they are generous producers. To keep them happy, I provide plenty of water and organic matter. They need mulching, which helps keep the water in, and they signal a need for more water by drooping their leaves.
Sunflowers attract grasshoppers and other insects, but a healthy plant will shake off the damage and grow past it. The fragile fancy sunflowers have trouble getting past the predation, so I do not care to plant them unless they are discounted 90%.
Sunflowers convert solar power more efficiently than corn, and corn is the champion. Moreover, sunflowers are tops on the list of nutrition - protein, vitamins, and oil.
In New Ulm my squirrels were not eating from the cute corn feeder because they got into the garage and ate from the sunflower bag in the plastic garbage can. I left the lid off. When I found the criminal in the act I secured the lid. He had a tantrum, leaving a deposit on top of the lid and a mess in the loft (my Garage Mahal). No wonder the squirrels looked so sleek and well fed - they were well fed with the best food of all.
Apart from the obvious bird and insect life, sunflowers have to be massive centers of life. They provide leaf and stem surfaces for spiders and other creatures. They dig into the soil and make deals with the soil creatures below.
Sunflowers are real divas. Their plants exude chemicals that keep other plants from thriving near them. That is because they know it is in their best interest to hog the soil and and the sunlight. Millions of years ago, they became sentient and figured this out, I am happy to report. (OK, I am kidding.) They were created to prosper in the sun and harbor all kinds of life, above and below.
Believers know this is God's design and will. Unbelievers cannot grasp it.
