Cosmos is one of the fastest-growing annual flowers. Some varieties reach up to six feet by summer's end.
Description: Cosmos forms a lacy, open plant with flowers three to four inches in diameter. These daisy-look-alikes come in pink, red, white, and lavender with a contrasting yellow center.
How to grow: Cosmos grows best in full sun, but it will bloom acceptably in partial shade. Space at least 12 inches apart.
Propagation: Because it grows so fast, sow cosmos outdoors after danger of frost has passed or three weeks earlier, indoors. Barely cover seeds; they need light to germinate. Germination takes three to seven days at 70 degrees to 75 degrees Fahrenheit.
Uses: Because of its height, cosmos should be planted at the back of borders and grouped against fences or other places as a covering.
Related species: Cosmos sulphureus is the source of the hot red and yellow colors of cosmos. Blooms come quickly after planting seed and continue until frost.
Related varieties: Sensation series is four feet tall and comes in mixed colors. Purity is similar in pure white. Gazebo is a two-foot mix.
Scientific name: Cosmos bipinnatus