Aster Identification

Asters are a flowering plant genus that derive their name from the Greek word "aster," which means star. They're strong and dependable plants that do well in dry regions. Although some aster varieties bloom in spring and summer, others produce flowers in fall, when many other garden flowers are spent. These plants are mostly perennials. Many gardeners enjoy growing asters because they attract butterflies to their gardens.
Identification
The aster's extremely long, narrow leaves can be somewhat hairy. These flowering plants resemble daisies, which are distant cousins. Many asters are white, although they can have a pinkish tint. They generally bloom from August through October and are one of the last plants to keep producing flowers in fall. Asters produce small seeds that resemble fleas.

Size
These plants come in various heights, but they generally grow from 6 to 8 inches tall, depending on the particular species and cultivars. Most aster cultivars are short, although others, such as heath asters (ericoides) can grow up to 2 feet tall, according to Dr. Leonard Perry of the University of Vermont Extension office. Calico asters (lateriflorus horizontalis), which are named for their many white and pink flowers, grow from 1 to 2 feet tall.

Types
Aster Starlights, often grown in patio containers and in borders, are compact flowers that produce spider-like blooms in purple, blue, rose and scarlet shades. The Astrantia Major "Florence" is known for its lavender-pin flowers that bloom in late summer and early fall.

The Astrantia major "Venice" cultivar produces striking ruby-red blooms that almost look burgundy. Aster Matsumotos have a star-like head and stunning flowers with brightly colored petals that encircle a yellow center.

Misconception
Although an aster looks like a single flower, it's really a collection of hundreds of tiny flowers, known as florets. Each aster flower has a center filled with flat orange or yellow disc florets. Colored petals are attached to the ray florets that encircle the perimeter of the florets. Besides white, the petals, which are usually 1 to 2 inches wide, may be red, pink, blue, lavender or purple, according to Jennifer Schultz Nelson on the University of Illinois Extension website.

Considerations
Asters need to grow in full sun in well-drained soil. These flowers are prone to developing several fungal infections, such as root rot, when there's excess moisture. Dig up asters and divide them every two to three years so they will continue to perform well, according to Nelson on the University of Illinois Extension website. Pinch or shear them back, periodically, through midsummer, so they can branch out and maintain their compact and bushy growth pattern.

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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.

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