Up for sale is one pack of 20 Mongolian Giant Sunflower seeds. These sunflowers are a novelty in the garden and make a great conversation piece as they grow 12 feet tall with a single stem giant yellow sunflower. CULTURE Soil temperature: 70 - 75 degrees fahrenheit Germination lighting: Dark required Germination days: 4 - 8 days Grow on temperature day: 55 - 60 degrees fahrenheit Plant spread: 24" Plant height: 12'+ Plant type: Annual Maturation days: 80 days These jumbo sized sunflowers require a little different soil preparation than the other sunflowers we sell. First step it to take a pitch fork and loosen your soil 12" deep. Next enrich you top soil and till 6" deep until your soil is the consistency of brown sugar. When soil is consistently 70 degrees (for zone 6-7 usually June 1st) plant seed 1/2" deep and a minimum of 12" apart and then top with a light dusting of compost. These are low maintenance and require nothing else other than weekly watering. Don't pinch like branching sunflowers as they are single stem. Unlike other sunflowers we sell you will get the best results if you use a slow release fertilizer, or top with compost monthly, as they use a lot of nutrients as they grow. We don't recommend you start sunflowers early in pots as they send a large tap root when germinating and in pots less than 6" deep will quickly become rootbound and not develop correctly. The overall vigor of the plant, is very dependent on sufficient soil nutrient levels.