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?!

Feeding Colorado

Deana Wise, Broomfield County

Every year the bounty of the garden seems to change. Some years there are so many tomatoes harvested, everyone is making sauces and salsas. Other years, many gardeners have given up on home-grown tomatoes; forced to wander the Farmer’s Markets and grocery stores. The one vegetable that always seems to thrive is Zucchini.

 Some gardeners are quite masterful in using this veggie in creative ways in the kitchen. Others take them to offices, churches, and other places where they are left on tables while the gardener makes a speedy exit. It is worse than trying to get rid of Iris.

One solution is to donate excess fresh veggies to the food bank. Ok, where? There are many food banks, food pantries, and other non-profit soup kitchens in Colorado. A good place to start is Feeding Colorado. According to their website “Feeding Colorado's purpose is to coordinate and enhance food resources among the state's food banks and to support the mission of Feeding America. The food banks are 501(c) (3) non-profit organizations. They receive broad community support from individuals, corporations, local governments, faith communities and corporations.” (http://feedingcolorado.org/ ).

Feeding Colorado is comprised of five large food banks: Food Bank of the Rockies, Community Food Share, Food Bank for Larimer County, Weld Food Bank, and Care and Share Foodbank for Southern Colorado. Together, they send food out to 1500 other nonprofit agencies. To find a food bank in your area use this link http://www.feedingamerica.org/find-your-local-foodbank/ .  H UD also has a website for foodbanks.

http://portal.hud.gov/hudportal/HUD?src=/states/colorado/homeless/foodbanks#Broomfield

I know this is a busy time for everyone, please take time to donate any excess fresh produce you have. Someone somewhere would love to have fresh veggies, even if it is Zucchini.

To-may-to, To-mah-to

 

Jane Rozum, Horticulture Agent, CSU Extension Douglas County

“...But though an old man, I am but a young gardener."  - Thomas Jefferson, 1811

I think of this quote every time gardening pulls a fast one on me. I refuse to think of myself as old (and it’s not polite to ask, I’ll remind you!), but I am often amazed when I follow all the researched-based information from CSU, and still find my skills as a gardener wanting.

Let’s take growing tomatoes as an example.

My new garden space seemed like a great place to start a small vegetable garden. Raised bed, decent soil (results from a CSU soil test) and ample sun. I started zucchini from seed, bought peppers and some tomatoes from a big box store and started to plant. While at a farmer’s market, I bought a few more heirloom tomato plants. A wonderful Douglas County Master Gardener shared a couple cherry tomato plants with me.

Though the garden was slow to start, the plant’s growth leaped once the weather turned warm. My heirloom tomato (Italian Heirloom) was gorgeous with large developing tomatoes. I was salivating with anticipation of those beautiful fruits. I wasn’t able to check my plants for over a week, but knew I’d come back to many large, deep red, sweet fruit.

When I returned to the garden, those beautiful tomatoes weren’t red, but a mottled reddish orange-yellow. What? How could this happen?

A closer look showed that the lush foliage had spots on the new leaves, which were also smaller and cupped.

My beautiful tomato plant had contracted Tomato Spotted Wilt Virus (TSWV). This is a serious disease of many plants, and my beautiful heirloom was infected. I didn’t notice if psyllids, a tiny insect that can transmit the disease was on the plant, but it could also have come from my transplants. What to do when you have TSWV? Pull the plant…and don’t compost and hope the other tomatoes have resistance and aren’t infected.  Lesson learned: Though I love heirlooms, I will now buy disease resistant varieties.

As I was mourning my loss, I also noticed other problems on my tomato plants. Early blight (photo2 ) is a fungal infection which tends to affect older leaves.  You can treat with sulfur dust, but I pruned out the diseased leaves and applied mulch around the base of the plant so the spores don’t splash up and infect more leaves.  Lesson learned: Get mulch around the base of the plants sooner, rather than later.

I also noticed that my Brandywine tomato had a blossom end rot on some fruit. I realized that consistent watering and fertilization or excessive heat (or cold) during blossom set may have caused the problem. Lesson learned: Practice consistent watering and fertilization  to prevent blossom end rot.

Is there any wonder that CSU has an entire fact sheet devoted to tomato-growing problems? Check out ‘Recognizing Tomato Problems’ if you have these and other symptoms on your tomato plants.

Maybe next year, I should just stick with zucchini. Now that’s a plant that just keeps on giving…and giving….

Hort Peeves: The "More is Better" Attitude

Posted by: Alison O'Connor, Larimer County Extension

Seriously!?!

Hopefully you did a double-take of the Japanese maple photo above. Perhaps a thought came into your mind that starts with, "What the _____?!" (You fill in the blank.) This photo was taken by my brother, Jeffrey, in Oregon. His text said, "What do you think? A few more scoops should do it?"

In case you're wondering what's wrong, that poor Japanese maple is covered (smothered, really) in Osmocote, a slow-release fertilizer. And this brings me to my hort peeve: the mentality that, "A little is good, so a lot more is better."

Here's the thing..."a lot more" can actually do damage to your plants. Whether it's fertilizer, pesticides or even water. Too much fertilizer can cause burning, salt build-up and excessive succulent growth that is more prone to insects, disease and damage. Overuse of pesticides is wasteful and not environmentally responsible.

Weed death by drowning.

Yes, we've all done it. Even I've done it. But it's not the way to approach sustainable (and legal) gardening.

The bottom line: Read the label and apply the product according to the directions. In terms of pesticides, the label is the law. If the label suggests to apply the product so that the foliage is "lightly dripping", do not pour the product on the plant. If the product suggests 2 teaspoons of product per inch trunk diameter, do not use 2 cups of product.

MORE IS NOT BETTER!

I realize that we're an instant society and we want to see immediate results. If we use Roundup, we want that plant dead within hours. As a point of clarity, glyphosate (the active ingredient in Roundup) usually takes a week or more to work, depending on conditions. But ingredients have been added (like diquat) so that you see foliage burn in a couple hours.

This also brings up another peeve: apply the product in the time frame suggested. If the label says wait 14 days before reapplying, then wait 14 days. Don't reapply at 7 days and think you'll "get a jump" on the problem. Give the product time to work.

Going back to the Japanese maple, Jeff has assured me he will keep an eye on it. I suspect the poor tree will show signs of leaf burn and dieback over the coming months/years. Poor tree.

Ugh.

The Leaves They Are A’Fallin’

Posted by: Mary Small, Colorado State Master Gardener Coordinator and Jefferson County Extension Office

Time to get out the rake....

Okay, can I just say I am sick of aspen and cottonwood dropping their leaves already?!

We’ve received numerous leaf samples from these trees and nearly all of them have been infected with either Marssonina or Septoria leaf spot diseases. It’s so severe in some places that some trees are already defoliated or darn near. It’s causing a lot of concern and unfortunately we can’t do much for the trees or their owners!

Caused by fungi, these diseases develop readily in cool, wet weather (like we had this spring).  Fungal spores are released from last year’s infected leaves.  Spores (the “seeds” of the fungus) are then blown or carried by splashing water to susceptible new tissue, causing infections. 

Septoria leaf spot on cottonwood

Although leaves are infected in the spring, symptoms usually don’t appear until mid to late summer. Leaves will drop prematurely.  Trees can be stressed during severe outbreaks due to reduction of photosynthesis and food production.

Symptoms vary between these two diseases. Marssonina leaf spots are dark brown dots with yellow halos.  In prolonged wet weather (which we’ve also had), smaller spots may fuse to form larger black patches. Septoria spots form under similar conditions and often occur alongside Marssonina. Septoria start out as dark sunken flecks that may enlarge and form larger dead areas or spots are tan and circular with dark margins. 

Marssonina leaf spot on aspen

One of the best times to manage the diseases is now, from late summer into fall. Where it is practical (such as in a landscape, rather than a forested setting), rake up fallen leaves and dispose of them in the trash. The diseases over-winter in the dropped leaves and raking and disposing removes that inoculum from the site for next year. (Unless of course, infected leaves/spores blow in from somewhere else!)

In the landscape, space plants according to recommendations for the species.  Trees planted too closely increase the humidity within the canopy, creating conditions ideal for infection. Keep sprinkler water out of leaves, so they stay dry.  Splashing water from sprinklers can also spread spores between leaves, causing secondary infections.  Prune to thin trees. This increases air circulation, keeping leaf surfaces dry. 

I could say we might hope for a drier year in 2016, but I won’t. Sorry, aspen and poplar. 

My Lawn is Turning Red?

Tony Koski, Extension Turf Specialist

Rough(stalk) bluegrass (Poa trivialis) will turn purple or
red when it becomes heat-and/or drought-stressed,
and then brown when completely dormant.

It’s been an interesting year for lawns. The cool wet spring gave us perfect growing conditions for bluegrass and other cool-season grass lawns – and perfect conditions for some diseases we don’t normally see here. Then it turned hot and dry, causing Ascochyta leaf blight to break out in epidemic proportions. I’ve written about yellow lawns and brown spots. Now we are getting calls and emails about red and purple spots in lawns.

Rough bluegrass turns brown when completely dormant.
While it looks dead, it will revive itself when cooler
weather returns in the fall.

The red grass people are seeing is rough(stalk) bluegrass (Poa trivialis) reacting to the very hot weather we’ve had the past couple of weeks. This cool-season relative to Kentucky bluegrass likes hot weather even less than our bluegrass lawns do – so it will often go dormant when we get long stretches of 90+ degree weather. Most often it just goes from green to brown, but it sometimes turns a bright red or purple before browning out. These red grass plants may have stopped producing chlorophyll in advance of becoming dormant (a “smart” thing for a plant to do), leaving red pigments behind – giving the plant a red appearance. Or they are producing extra xanthocyanins and carotenoids (red, purple and pink colored pigments) to protect the leaves from excess light (kind of a sunscreen that the plant produces to protect itself). Either way, the Poa triv patches in some lawns (usually in the hottest, sunniest parts of lawns) take on a reddish or purple cast – before turning a dead-appearing brown.

While it may appear to be dead, dormant Poa triv
will come back from live stolons on the soil surface. You
can find these green stolons when you dig down into
the patches of dormant, brown grass.

In spite of the dead appearance, the grass is only dormant. When cooler weather returns, it will green up again. Triv will often go dormant when it’s hot, in spite of generous irrigation. It’s not a drought-induced dormancy, but rather a heat-induced one.

This happy, green Poa triv is growing in a shady spot
just a few feet away from the brown patch pictured
above. It is aggressively and successfully crowding out
the original grass - turf-type tall fescue.

When you have a lawn full of Poa triv, you either learn to love it (or at least tolerate it), or you kill it and reseed or re-sod. There is no selective herbicide that will eliminate this weedy grass without harming the bluegrass or ryegrass in the lawn. Poa triv spreads easily and quickly by creeping stolons (runners) to form large patches - especially in lawns that are kept on the wet side. Shade favors its growth, but it can grow quite well in full-sun (but is more likely to go dormant in the sunnier parts of lawns). It is an aggressive, smothering grass under optimal conditions (wet, cool, shady), but less aggressive in drier, sunnier lawns.

I’m hoping for some cooler, wetter weather that will give us healthy, GREEN grass again.

Why I love floating row covers

Posted by Irene Shonle, CSU Extension in Gilpin County

As a mountain gardener, I believe that floating row covers are my vegetable garden’s best friend.   I wrote an “ode” to them in the Mountain gardening blog: http://coloradomountaingardener.blogspot.com/2013/06/an-ode-to-floating-row-covers-by-irene.html

This year, I have a new reason to love them: hail.   We got a spectacular hail storm in July, with about an inch of graupel and a couple inches of rain falling in less than an hour.  We still had a pile of hail under our downspout three days later.

The weight of the hail pulled the row cover off a corner of my row cover, and where the tender spinach and lettuce was exposed, it turned to mush:

The spinach underneath was untouched (which, thankfully, was most of the bed).  Hooray for floating row covers! 

I had tried an experiment this year where I planted red mustard and squash in the same bed.  I figured I’d be harvesting the mustard as the squash grew larger, so it was a good use of space. Just as the squash was starting to flower, I took the row cover off to allow for pollination.  I was planning on cooking up a mess of greens for dinner, but the hail hit before I harvested.  Bad timing!  Shredded mustard.  I tried salvaging a few of the leaves to cook, but the rain had been so intense, it was impossible to wash all of the imbedded grit off.    The squash leaves were skeletonized as well. Fortunately, almost everything recovered pretty well within a couple of weeks.  

This is probably one of the only downsides to floating row covers – the need to remove them for plants that require pollination.  Okay, and the cute factor goes down a bit, too – but I’d rather have nice greens than cute.