Do Flowering Aster Plants Come Back Every Year? Here's How To Keep Them Growing

Perennial flowering plants are effortless and reliable. They return every year and come in all shapes, sizes, and colors. But when picking perennials, some people wonder if the daisy-like flowering aster plants actually come back every year. And the question makes sense. The aster name applies to two distinct groups of plants — one is an annual, and the other is a perennial. 

The first group of asters is the China aster (Callistephus chinensis), which has an annual life cycle and can be grown pretty much anywhere in the U.S. in early spring. The other group of Asters is native to the U.S. and has a perennial life cycle. Botanically, they are known as Eurybia or Symphyotrichum. And, unlike the China aster, they are mostly grown as perennials in USDA Plant Hardiness Zones 4 to 8. Outside these zones, though, you can grow them as annuals for some single-season color. Nevertheless, if you plant them in the right zone and know how to grow and take care of your asters, they will keep coming back every year to fill your garden with color and scent.

If you want your perennial flowering plant to thrive and come back every year, you have to provide it with the right conditions.And when it comes to asters, the light, soil, and moisture needs vary between different types. So, make sure you know what kind of Aster you are getting before starting a beautiful flower garden. If you are planting them for the first time, put them in the ground at least six weeks before the first frost. This will give them adequate time to develop a robust root system before the ground freezes over.

No matter the soil type, all asters need a well-draining soil with good ventilation, as they can be prone to fungal diseases like powdery mildew. Most asters prefer full sun, and only need watering about once a week. 

Asters need to be divided every two to three years. Otherwise, they get clumpy, and their centers begin to die. Regular pruning will also help asters come back each year. Asters range in size from only a few inches to six feet. The taller varieties can be pruned a few times during summer to improve flowering. Cease pruning in late July, and don't prune during midday, especially when it is sunny outdoors. It is a huge mistake to prune in direct sun as it stresses the plants. Furthermore, make sure not to over-fertilize or plant asters in overly rich soil, as this can reduce flowering. If you want the flowers to stay for longer, stop fertilizing once they appear.