Varieties of Giant Sunflowers:

There  number of varieties of giant sunflowers. Here are a few of them:

Mammoth - Perhaps the best known of the giant sunflower varieties. Many believe it is also the best looking of the giant sunflowers. An enormous head, more than a foot across, sits atop a 7-12 foot plant. Seeds are great for roasting, too.

American Giant Hybrid  -  This variety produces very tall plants. The head is not as big. The plant grows up to 16 feet. Blooms are approximately 10 inches in diameter.

Skyscraper -  Grows a very big flowerhead of 14 inches across or more. The plant grows about 12 feet .

Days to Maturity: 75 to 90 days, or more

Propagation:

Giant sunflowers are grown from seed. They can be started indoors, or directly seeded into the garden. If you start them indoors, do not let them get root bound. Carefully transplant them into their summer home as soon as possible.

Final spacing of plants should be 2-3 feet apart.  If you are growing them to get them as big as possible, we recommend a full three feet, so the plants do not shade each other.

How to Grow Giant Sunflower Plants:

Giant Sunflowers need to be grown in full sun. Soil conditions can vary, from average a to rich soil. To produce optimum growth, the soil should be very rich. The richer the soil, the better the plant growth. The soil should also be well drained. Dig a hole two to three feet deep. Fill it with layers of compost, regular garden soil, and manure. This will help to promote optimum plant growth.

One of the important ingredients to fueling giant growth, is a regular supply of fertilizer. Begin your fertilizer regimen with a high nitrogen formula. If you are growing sunflowers for record height, continue the high nitrogen formula all season long. For big blooms, switch to a high phosphorous formula, as the plant nears its expected height and the flowerhead begins to form.  

Give your plants a regular supply of water. Deeply water your plants, to assure it gets to all of the roots. Do not allow the soil to dry out. And, do not soak the soil.

Staking giant pumpkin plants is very important. These tall, heavy plants are susceptible to falling over on windy days. The stake doesn't have to be as tall as the plant. But, it should be several feet tall, and anchored firmly into the ground.

Insect and Disease:

Sunflowers experience few insect and disease problems.

Ants may be frequent travellers up and down the stalk. They usually do no do any serious damage to the plant.