Shazam! Plants that Shine in Fall

Posted by: Alison O'Connor, Larimer County Extension

It's always around this time of year when I look around the garden and have a hard time finding anything that makes me swoon. Most plants just look a bit....tired. Like their gardener. The iris have flopped. The coneflowers are fading. The annuals are waiting for the first frost. But looking a bit closer, you find certain plants that are just ramping up for the fall.

Here's a (very short) list of some of my favorites, but please share the ones you love.

We have to kick it off with ornamental grasses. These tough, beautiful plants really make you turn your head in the fall with colorful foliage and flowers. There's a great ornamental grass for any landscape and there's a national study where CSU is a partner with numerous other sites across the U.S., looking at various species of ornamental grasses. Fellow CO-Hort Jane Rozum did her Master's work looking at water use of these plants.

Two of my (current) favorite ornamental grasses are Blonde Ambition blue grama (Bouteloua gracilis 'Blonde Ambition') and Shenandoah switchgrass (Panicum virgatum 'Shenandoah').

Blue grama is a native of Colorado and Blonde Ambition is a selected variety. The dancing "mustaches" (or eyebrows) gently bob on top of delicate foliage. It's so freaking cute, I can barely stand it. I love this grass. I planted three in my yard last year, so they are still pretty small. One worry I have is this is being planted everywhere. Even in the Costco parking lot islands. Will it become the next Karl Forester?

There's a lot going on in this photo, but Blonde Ambition is in the middle with the straw-colored "mustaches". To the left is orange carpet hummingbird trumpet; behind is Paint the Town shrub rose; to the right is  blue fescue.

Shenandoah is stunning. The foliage turns burgundy-purple as cooler weather sets in. The dainty pink flowers sit atop the plant, which will reach about 3-4' tall at maturity. It's fabulous. I adore this grass. It's a great size, tough as nails and is pest-free. I made a "happy accident" (thanks, Bob Ross!) and planted it near a sedum that picks up the pink inflorescences.

Nosy Maple is sniffing out the sedum and Shenandoah switchgrass. The foliage will continue to develop a deeper burgundy color as fall progresses. 

Two vines really shine in the fall. One is Sweet Autumn clematis (Clematis terniflora), which is a vigorous grower and has tiny white flowers that cover the plant, like a blanket of snow. My Sweet Autumn died back to the ground during winter and went nuts this summer, covering the pergola it's planted by. Bonus--it smells nice, too!

Sweet Autumn clematis. This is a nice clematis to plant, since it blooms so late in the summer, unlike some of its cousins. 

The other vine that deserves a nod is silver lace vine (Polygonum aubertii). Now, this plant isn't for everyone. It's very aggressive (borderline invasive) and can quickly cover any territory it's planted near. This one happens to be on our corner fence....but every spring I have to yank, pull, prune and hack to tame the vines. I once peeked through the fence and it's growing a good five feet into my neighbor's back yard. So plant with caution, but if you have the space, you'll enjoy the fall show!

I think it's safe to say that the silver lace vine has pretty much eaten the fence. Pretty though!

Finally, many sedums bloom late in summer and have attractive flowers and foliage that jazz up the fall landscape. Angelina sedum (Sedum rupestre 'Angelina') is lime green during spring and summer and turns copper with cooler weather. What I love about this plant is how it finds pockets of bare earth and gently fills in to form a dense mat. I noticed that the wet spring caused some of the plants to die out, but they will recover next year.

Angelina sedum. The lime green foliage turns copper with crisp fall weather.

A larger, more upright sedum with variegated foliage is Frosty Morn sedum (Sedum erythrostictum 'Frosty Morn'). This plant was covered in honeybees and other pollinators--it was a heyday. Reaching about 18" tall, the stout flowers are so large, you wonder how the plant can stay upright. But the variegated foliage and pink flowers are a wonderful compliment to each other.

Frosty Morn sedum. I love variegated plants...and the color pink. What more could I ask for in a plant?

There are, of course, many other plants that are spectacular in the fall...phlox, mums, Joe-pye weed and more. These are just a few that caught my eye as I looked around my tired garden. Why is it that my good plants are fading, but the weeds are healthier than ever?!