How to grow and care for native Asters

Three native asters: Ideal plants for our natural gardens

Our native asters are stealing the show in the meadows and open woodlands around our home reminding us that, if we are not already growing them in our gardens, its time to plant them for next fall.

In our garden the wood asters have made an appearance along with the Woodland Sunflowers, goldenrod and Black-eyed Susans across the back area of our garden.

Do Wood Asters attract pollinators?

The White Wood Asters (Eurybia divaricata), also known as Heart-Leaved Aster, are delicate whitish-blue flowers that add an airy feel to the garden and the perfect excuse for the small pollinators – native sweat bees and small butterflies as well as other insects – to stop by and enjoy a late summer harvest.

New England Asters growing in a naturalistic setting. What some people may think of as a weed, are actually beautiful native wildflowers that are vital to native bees and wildlife.

Embrace these plants and the somewhat messy look they sometimes bring to your garden and focus on the wildlife that find your garden aesthetics just perfect – because it is perfect – for them.

These perennial plants grow between 30 to 90 centimetres (12-35 inches) tall, with heart shaped leaves on the lower parts of the plant and changing to more elongated and deeply serrated on the upper reaches of the plant.

For more information on native plants, check out my earlier articles: 35 native wildflowers and Why we need to grow native plants.

If you are thinking about growing your own meadow garden, be sure to check out garden designer Angela den Hoed’s meadow garden and her five favourite plants for the meadow garden.

White wood asters, New England asters combine beautifully with goldenrod.

How to grow Wood Asters

These are a form of shade-loving asters that can be found growing naturally in dry, organic-rich woodlands and on the edges of forest areas in part shade.

Ours are growing happily on the edge of our ancient crabapple trees, where conditions seem almost ideal for them.

Although these asters will tolerate full shade or sun, they are happiest in part shade. Their beautiful, yet delicate branching clusters of pale blue flowers give a nice airy feel to the garden as well as providing a good source of nectar and pollination for both bees and butterflies.

• Hardiness Zone: 3-7

• Light: Part shade to full sun

• Moisture: Tolerates dry soil, shade to part shade neutral to slightly acidic conditions.

• Soil: clay loam to sandy loam, organic

• Mature Height: 3-feet-high

• Growth: Vigorous or aggressive, even in dry shade.

• Propagation: Can be started from seed (seeds mature in late fall), by dividing clumps in early spring or allowed to spread entirely on its own.

This informative infographic designed by Justin Lewis shows the value of the New England Aster.

Are Wood Asters a threatened species?

The Wood Asters’ range is quite broad despite its extremely limited range in Canada where it is confined to a small number of sites in the Niagara region and in more southern areas as well as a few woodlots in southwestern Quebec.

In the United States the Wood Aster ranges from New England south into Georgia and Alabama.

In Ontario, according to the government’s website, the Wood Aster has been considered a threatened species since before 2008, meaning that the plants are not yet endangered but are on that path if action is not taken.

All the more reason to plant some of these delicate little flowers in your garden.

The government website adds these quick facts about the Wood Aster:

• White wood aster seeds are dispersed by the wind but are generally not carried for long distances; this may account for its low colonization rate and restricted range

• White wood aster is also known as the Heart-leaved aster because of the shape of its lower leaves

• The flowers of White wood aster are attractive to butterflies and it is the host plant for Pearly crescents, a common North American butterfly

Right on cue our plants began to flower in mid September with their yellow and purple florets surrounded by the white petals.

The White Wood Aster likes to grow in colonies where it spreads via underground roots.

The plant’s decline in Ontario and Quebec is attributed to a number of factors, including habitat loss as well as competition from increased recreational activities ie: trampling by hikers, bikers and ATVs. Deer grazing and competition from invasive garlic mustard are also putting stresses on the plant in natural settings.

New England Asters in a naturalized setting growing among native grasses.

New England Aster: Dominant flower along roadsides and open fields

New England Asters are happy growing in part shade to full sun in our gardens and naturalized areas along our roadside and open meadows.

Plant them in sandy loam and these late summer/fall bloomers will reach heights of 5 feet with impressive, purple blooms sporting orange centres.

By cutting back the plant in mid-summer (Chelsea Chop: Link to Fine Gardening article), it’s possible to keep the plant a little more manageable throughout the fall.

New England Aster, like all late-blooming perennials, is a critical source of late-season nourishment for pollinators. If you have ever observed the plant in late summer, its attraction to native bees, butterflies and other insects is noteworthy.

New England Aster is distinguished from Smooth Blue Aster by its hairy stem.

Good companions plantings for New England Aster

If you have a meadow garden, consider pairing this aster with Goldenrod, Oxeye daisy, Woodland sunflower and late-season grasses.

!

Large Leaved Aster is another winner in the woodland

Large Leaved Aster (Eurybia macrophylla) grows in part shade to full sun in zones 3 to 9. It prefers a sandy loam with medium moisture and will grow to about 4 feet tall.

This is another shade-tolerant aster that can work in a woodland-style garden. Consider planting them on the edges or in small clearings where they can benefit from some sunny periods.

The plant’s pale blue blooms are secondary to the 4-8 inch heart-shaped basal leaves that form almost a ground-cover-like carpet.

In conclusion: Asters are important in our landscapes and natural areas

It’s easy to disregard the importance of Asters in our landscapes. Many gardeners focused on aesthetic, non-native gardens would consider the plants weeds and eliminate them as soon as they seem these perennials encroaching on their gardens.

This approach is one of the main reasons asters are disappearing in gardens and open meadows throughout North America and Europe.

In turn, our native bees, butterflies, caterpillars and other insect numbers are falling and threatening the health of our birds that depend on these insects to survive and feed their young.

As woodland or naturalistic gardeners, it is rewarding to know that we are doing our small part to restore the ecosystem and protect plants that are either threatened or spiralling downward.

Embrace these plants and the somewhat messy look they sometimes bring to your garden and focus on the wildlife that find your garden aesthetics just perfect – because they are perfect.