September is here, and with it our gardens begin to fade, the crescendo of summer blossoms has passed us by, and now the purple and golden fields of asters, ironweed, and goldenrod are heralding summer's end.
The big flush of summer color is winding down, and suddenly there just are not as many flowers in the garden as there were a few weeks ago, but this is when we our pollinators need their last push of fuel before migration, or hibernation.
That makes this one of the best times to pay attention to what is missing in your own garden. If you are wishing you had more blooming right now, this is the perfect time to plant for that gap.
Late summer and fall are excellent times to establish perennial plants, and planting late-season bloomers now can help extend your garden's flowering season next year and for years to come.
And while those extra blooms make the garden more beautiful, they also help provide an important late-season food source for the pollinators still active as summer gives way to fall.
Late-Season Blooms Matter
By late summer and fall, pollinators are still active.
Bees, butterflies and other beneficial insects continue to need reliable sources of nectar and pollen even as many summer flowers begin to disappear.
For migrating butterflies, including monarchs, late-blooming flowers can provide important nectar along the journey south. Native bees and other insects also depend on flowers that continue blooming well into the season.
Keeping pollinators and other beneficial insects well fed throughout the season can also benefit the garden itself. When bees, ladybugs, hoverflies, wasps, beetles and other helpful insects have a steady supply of flowers, they are more likely to keep using your garden as habitat. That means more pollination for fruits, vegetables and seed-producing plants, while many beneficial insects also help keep pest populations in check by feeding on aphids, caterpillars and other common garden pests.
A garden that flowers heavily in spring and early summer but goes quiet by August or September leaves a real seasonal gap.
One of the best ways to fill it?
Asters. And We Have A Lot of Them.
One of the reasons we love native asters is that there really is not just one kind of "aster."
Our native asters grow in an incredible range of habitats, which means you can find asters for hot sunny beds, dry slopes, woodland shade, rain gardens and low wet areas.
Instead of asking, "Do I have room for an aster?" the better question might be: Which aster belongs in this spot?
Got a Sunny Spot?
You have plenty of options.
New England Aster is the big, classic late-season showstopper, growing tall and producing masses of purple flowers when much of the summer garden is winding down. It is wonderful toward the back of a perennial border, in a pollinator garden or mixed into a meadow-style planting.
Aromatic Aster is a great choice when you want something lower and bushier. Established plants can become absolutely covered in lavender-purple flowers in fall.
Sky Blue Aster and Smooth Blue Aster bring softer blue-violet flowers into the mix and look especially beautiful planted among warm-toned grasses and goldenrods.
And if you want white flowers to break up all that purple and blue, Heath Aster produces clouds of small white blooms with a lighter, airier look.
Hot, Dry or Tough Spot?
Do not give up on late-season flowers just because the soil dries out.
Aromatic Aster is especially useful in sunny, relatively dry conditions once established.
Heath Aster is another excellent candidate for leaner, drier sunny sites.
Sky Blue Aster can also be a great fit for sunny sites with well-drained soil.
And, my personal favorite, 'Snow Flurry' Aster gives you something completely different. Rather than growing into a tall upright plant, it stays much lower and spreads outward, producing masses of small white flowers. It can be beautiful near the front of a bed, interplanted as a ground cover, spilling over a wall or anywhere you want snowy, soft, late flowers without a lot of height.
These are the kinds of plants that can turn a dry, tired-looking corner into one of the most lively parts of the garden in fall.
Need Flowers in the Shade?
A lot of gardeners assume that big displays of flowers require full sun. Not necessarily.
Big-Leaved Aster is made for the woodland garden. Its large leaves create a beautiful ground layer beneath trees and shrubs, followed by late-season flowers.
Drummond's Aster is another excellent woodland and woodland-edge species.
Short's Aster also works beautifully along woodland edges and in partially shaded gardens, adding flowers to spaces that may have been finished blooming for months.
These are especially useful if your spring woodland garden is wonderful but feels a little empty later in the year.
You can have a shady garden with real fall interest.
Have a Rain Garden or Low, Wet Spot?
There is an aster for that.
Swamp Aster naturally handles moist conditions and is a great plant to consider for low areas, rain gardens and other spots where the soil stays wetter.
New England Aster also appreciates soils that do not get excessively dry and can be a strong choice in sunny, moisture-retentive areas.
These plants let you work with a wet part of the landscape, holding soil and providing habitat where other plants may struggle.
Why Plant Several Different Asters?
Instead of putting one aster in the garden and calling it done, you can match different asters to the different little habitats already present in your landscape.
Put Aromatic Aster in the sunny border. Use Heath Aster or Sky Blue Aster in a drier area. Let Big-Leaved Aster, Drummond's Aster and Short's Aster carry the woodland edge. Put Swamp Aster into the wetter ground. Use Snow Flurry down low. Let New England Aster rise behind everything else.
Now asters are not just one patch of flowers. They become a late-season layer running throughout the entire garden.
And because different species have different habits and flowering periods, planting a diversity of asters can help keep something blooming for much longer.
Add Goldenrod and It Gets Even Better
Once you have all those purples, blues and whites, add yellow.
Asters and goldenrods are one of the greatest combinations of the late-summer and fall landscape, and they are both valuable sources of late-season food for insects.
We grow a broad selection of goldenrods too, including Showy Goldenrod, Sweet Goldenrod, Wrinkle-Leaf Goldenrod, Zigzag Goldenrod, Early Goldenrod, Grass-Leaved Goldenrod and 'Golden Fleece' Goldenrod.
Just like asters, there is not one goldenrod for every situation.
Some prefer open sunny sites. Some work in moister soil. Zigzag Goldenrod can even bring that bright yellow color into a woodland or partly shaded planting.
And despite a common misconception, goldenrod is generally not the culprit behind fall hay fever. Goldenrod pollen is relatively heavy and transported primarily by insects. Wind-pollinated ragweed blooming at the same time is much more commonly responsible.
Why Plant Them Now?
Fall is one of our favorite times to establish perennial plants.
The worst summer heat is passing, but the soil is still warm enough for roots to grow. Instead of immediately putting energy into surviving hot weather and producing flowers, a newly planted perennial can begin settling into its new home.
You may not see a huge amount of growth above ground before winter. That is okay.
Keep newly planted perennials watered during dry spells while they establish, and let them spend the season building roots.
Next spring, they are already in place and ready to grow.
Look at Your Garden Right Now
Where did the flowers disappear too early? Which sunny bed suddenly looks tired? Which shady corner has not bloomed since spring? Is there a dry slope that could use some life? A wet low spot you have never quite known what to do with?
If you wish something were blooming there right now, select some of these plants that naturally bloom at this time of year and plant them this fall.
By this time next year, you could be watching the next round of blossoms just getting started.
