Sunday, September 14, 2014

Late Season Native Flowers

Flowers that power their way through hot and often dry days are some of the most welcome ones that I have. By late summer it is hot and I am irritated with pesky mosquitoes, so the last thing I want to do is have to water flowers just to keep them going. 

These Solidago rugosa 'Fireworks' plants only get rain.

Hummingbird on cardinal flower
This blog post, therefore, is an ode to and a celebration of the native flowers that keep our gardens and roadsides alive with color and insects from late summer to fall. Without them our gardens would look like most highway roadsides – dull green and devoid of life.

The first one to kick in for me is cardinal flower (Lobelia cardinalis) when it starts blooming in July. As the weeks go on, the stalk gets longer and longer, blooms opening from bottom to top. It’s like a never-ending red candle.

The hummingbirds love it, of course. I have let it go to seed for many years and now have enough plants to have blooms well into September (plenty even today).

Cloudless sulphur on Lobelia cardinalis

I would consider it a 3-year perennial before it gets too big or the stem weevils (or whatever they are) get to it. The cloudless sulphur butterflies are particularly fond of it.

Bee on Lobelia siphilitica

Blue lobelias bloom a little later and are a gorgeous complement to their red cousin. The great blue lobelia (L. siphilitica) has thick clusters of fat flowers while the downy lobelia (L. puberula) has fewer blooms along a tall purple stem.

The shape of the blooms attract different pollinators. Bees love the great blue while skippers prefer the downy.

Skipper on Lobelia puberula (L. cardinalis in background)

I’ve written about summer perennials before, but in reading that post now I realize it was all early summer perennials - they are long gone by now. While there might be a few black-eyed Susan (Rudbeckia hirta) blooms hanging around, it is another Rudbeckia that shines in late summer: Rudbeckia fulgida var. fulgida, known as orange coneflower. They have spread themselves with abandon along my side yard and sprinkled into a few of the front areas.

Rudbeckia fulgida var. fulgida

Conoclinium coelestinum
As if to accentuate the orange coneflower even more, bright blue mistflower (Conoclinium coelestinum) has filled in any spaces that the Rudbeckia left behind. Until the flowers open I always wonder if I let it go too far. Once those puffy flowers are revealed, I forget all about thinking it was too much. It is also deer resistant so I don’t have to use any spray on it.

Mistflower used to be a Eupatorium and I can certainly see the resemblance in another of my other late summer perennials. White snakeroot (Ageratina altissima) was also a Eupatorium once. The bright white blooms are a welcome sight in September. It is also deer resistant although the fawns might take a small bite before realizing they don’t like it.

Eupatorium serotinum

Those plants that got to keep the Eupatorium name are a very hard-working bunch. Eupatorium album blooms in early summer so it is done by now, but late thoroughwort (E. serotinum) lights up the roadsides and decorates my garden. I let a volunteer by the front walk grow as much as it wanted this year and it grew to 8 feet tall! Heavy rain knocked it a kilter but the pollinators don’t care if it is leaning.

Eupatorium hyssopifolium is another favorite of mine. I met it on the roadsides near my house and brought a few home with me. It is much shorter than E. serotinum and wonderfully suitable for gardens. The finely textured foliage is very attractive too.

Helianthus angustifolius

I’ve also written separately about late summer yellow flowers, but most of them are gone by September. One exception is the singularly spectacular swamp sunflower (Helianthus angustifolius) which is just starting to open this week. September and into October is the time for this giant perennial.

Maryland aster (Chrysopsis mariana)

Silkgrass or goldenaster (Pityopsis graminifolia) is opening now. While a bit of a thug in well-watered gardens, it plays well with others in the drier areas of your yard. Another fine goldenaster is also called Maryland aster (Chrysopsis mariana). The stiff stems hold clusters of small yellow flowers. 

Eurybia spectabilis

Sprinkle in the purples of blazing stars (Liatris), asters  (Symphyotrichum and Eurybia) and ironweed (Vernonia  spp.) and you have some amazing combinations.

Of course it would not be fall without goldenrod (Solidago). I could go on forever about that wonderful genus but I already have so please just go read that old post.

I hope this has given you some ideas of new things to try. Fall native plant sales are upon us and this is a great time to be looking for things to fill those design holes in your garden.



  1. I'm surprised by how many flowers you have in common with what I see in Virginia. You mention weevils or something getting your cardinal flowers. What does it look like when this happens? This summer my cardinal flower leaves turned dark with a lot of spots on them, and then the plants wilted and died. However, I never noticed an insect pest on them. It was disappointing, but seedlings are popping up nearby, so life goes on.

  2. Hi Leah, what we have seen (and I'm not the only one) is that some bug burrows into the base of the stem and starts eating and going up the stem. I haven't seen leaf damage, but at some point the plant falls over and the bug damage is revealed.

  3. That sounds very much like the squash vine borers I've been warned about. It'll give me something else to watch out for. My cardinal flower problem seems to be something different--perhaps even a virus or fungal disease.