What Is an Aster Flower?

Asters are fall-blooming perennial flowers. They are often planted to compliment other fall blooming flowers such as chrysanthemums. Asters range in height, size and color, but all have a daisy-like flower. The name "aster" is derived from the Greek word for "star" due to the shape of the bloom. A few varieties can start blooming in the late spring or summer.

Varieties

Asters are divided into two main types: the New York (Aster novi-belgii) and the New England (Aster novae-angliae) varieties. New York types generally only grow to about 1 foot tall, but can be as short as 6 inches, while the New England Varieties average heights of about 2 to 3 feet. Many of the most common varieties available are descended from those developed by a Swiss nurseryman named Frikart. Frikart's asters are hardy down to USDA zone 5.

Flowers

Aster flowers are not actually one individual bloom, but rather a conglomeration of hundreds of tiny florets. These florets collectively form a blossom that is usually 1 to 2 inches in diameter. Single petals are attached to each floret in a range of colors. Asters can be white, blue, purple, red, pink or various shades of each. Though the flowers resemble those in the chrysanthemum family, asters are actually related to sunflowers.

Optimal Growing Conditions

Asters like to be planted in an area that receives full sun. They do not tolerate continual moisture and should be in a well-drained soil. This also helps prevent getting heaved out of the ground due to frosts. When planting, space 1 to 3 feet apart to allow for proper growth. Additionally, they should be cut back by approximately 1/3 every summer to encourage bushier growth and more flowers. Asters benefit from a spring application of fertilizer as well.

Pests

If asters are kept too wet, they can develop root rot or a disease known as "aster yellows" where the plant is stunted and turns yellow. Remove any infected plants to avoid spreading the disease to other asters or plants. Powdery mildew is another common disease of asters. Spray fungicides preventatively starting in June to help prevent the disease's development. Systemic insecticides should also be used to prevent and treat infestations of sucking insects such as lacebug.

Source: http://www.ehow.com/info_8545278_aster-flower.html