When gardeners think of fall flowers chrysanthemums usually come to mind but if you love mums you should consider trying Asters too. Asters are easy to grow and bloom in the fall when color is at a premium after summer perennials have faded. Just like mums Asters make good flowers for centerpieces and vases as their blooms remain intact long after they are cut.
Asters are perennials, which means their beauty returns year after year but they often need to be divided and replanted every 2 to 3 years in the spring to keep them growing vigorously. Aster flowers resemble daisies in terms of their shape and come in a range of colors including blue, purple, red, pink and white. They are hardy in USDA zones 3 through 8 and their height can range from 2 feet to 7 feet tall depending upon the variety that is grown.
While asters are relatively easy to grow they do have some requirements that need to be kept in mind to help them bloom their best. First, the soil they are planted in should be moist it should drain well as overly wet soil will kill asters. Asters also can be subject to moisture related diseases such as rust and powdery mildew so spacing that promotes good air circulation is a must and watering the leaves should be avoided. Asters also should not be fertilized more than once a growing season as too much fertilizer will promote a lot of growth but not a lot of blooms.
Finally, because asters can grow relatively tall they need to have some support to help them from flopping over. I usually install 4 strong stakes such as those made of bamboo in a square or diamond shape around the asters early in the spring and install string connecting the stakes every few weeks until June or July. This provides support to the asters and allows the asters to grow around the stakes and hide them from view by the time their blooming period starts. An additional way to keep asters from growing too tall is to practice something called pinching. Pinching involves removing the growing tips of the plant every few weeks so that the plants start to form branches. You can continue to pinch asters until around mid-July at which time you should stop pinching them and allow them to set flower buds.
Due to their height many varieties of aster can be used in the rear of your flower beds although lower growing varieties can be planted right up front. Asters obviously combine well with mums as the bloom at the same time of year but asters also go well with ornamental grasses. Other than a little staking and pinching asters are easy to grow and require no greater maintenance than other perennials. So, why not plant some asters and don’t let the chrysanthemums get all the attention.