Monday, May 15, 2017


I've grown several forms of Primula over the years. Sometimes with success and sometimes not. Those successes and failures have slowly taught me what most Primula need to do well in my gardens. What I learned was that most like gritty well-drained soils, cool temperatures, good fertility, and consistent moisture. While this is a generalization too broad for a genus of over 400 species and countless hybrids, it fits with many of the types readily available in garden centers. Having had success with several types now, I decided that maybe it was time for more varieties.

P. Pacific Giants Mix
Recently I put out a request for reliable sources for Primula seed on Facebook, and my friend Amy kindly offered to send me some seed if I just donated postage to the American Primrose Society. I expected maybe 5 or 6 packets of seed. When the envelope arrived, I opened it to find 19 packets of seed for a wide range of different species and varieties. Postage was $.98. I messaged Amy and thanked her for her generosity, but told her I couldn't donate just a dollar to APS for such generosity. She agreed that APS membership was a suitable payment, so I joined.

P. 'Blue Zebra'
One of the neat things about the APS is that they've been around since 1941 and publishing a newsletter since 1943. Most of those newsletters are available to the public on their website. That's over 70 years of journals about the genus! I also picked two new books. One, The Plant Lover's Guide to Primula, is great for anyone who wants to learn more about the genus from a gardeners perspective. The other, Primula by John Richards, is the definitive work on the genus and is probably best for hardcore Primula lovers and other botanically oriented people. Both are excellent books that I'm excited to have added to my library.

I want to share a bit of information that I've learned over the years and recently in my reading. The APS journals and my new books have helped clear up some terminology that I never really bothered to delve into before. As is often the case, what's often advertised in garden centers and box stores isn't necessarily correct or complete information. I also want to share how to grow some of the readily available types I've sold and grown over the years.

The most common type you find for sale at garden centers usually are labeled as P. vulgaris or P. polyanthus. These are not true P. vulgaris, but are hybrids involving P. vulgaris, P. elatior, P. veris, P. juliae and others. Polyanthus isn't actually a species, but rather a descriptor of flower type. They are popular spring flowers in garden centers and usually found as mixes like Crescendo, Pacific Giants, or Supernova. Sometimes you can find them as specific colors from the series (ie Crescendo Blue Shades). Each of these series are slightly different, and all are very hardy - usually to z3.

There are two basic ways the flowers are held on this group of hybrids. Polyanthus types have a cluster of flowers on a stem. The mentioned series above all fall under the Polyanthus group as do the species P. elatior and P. veris. Acaulis types have flowers that are held on stems individually, and many varieties fall under this category such as the Belarina series and the species P. vulgaris.

These plants are all pretty easy to grow, which is one reason they're so popular. They like a woodland soil which is well-drained to prevent being waterlogged in winter but with plenty of organic matter for moisture retention during the growing season. They also do best with some afternoon shade and can't be allowed to dry out in the summer. I've grown a lot of these. I've also killed a lot of them, but I have a pretty good handle on keeping them happy now. In my case, improving the drainage of my clay loam with pine bark and making sure I watered them regularly was the key.

P. elatior

P. veris
P. Supernova Blue

P. Supernova Purple
P. Supernova Mix

P. Supernova Mix

And acaulis type Primula

P. Belarina 'Valentine'
P. Belarina 'Cobalt Blue'

P. Crescendo White

P. Crescendo Yellow and Crescendo Red

P. Crescendo Blue
P. Crescendo Mix
An acaulis type Primula
Primula denticulata is the first species that I really had good success with. It likes similar conditions to the previous group: well-draining woodland soil and a little extra irrigation in summer. I found the species to be a little more forgiving about surviving summer dryness, but it's naturally found in fairly moist sites. This species blooms about the same time as the vulgaris hybrids, but grows a bit taller - up to a foot. The foliage can get quite large after blooming if the plant is happy. It tends to be  vigorous species growing two feet across or more and can self-sow around the garden if conditions are good. The dense spherical clusters of white to purple flowers make this a really popular species.

P. denticulata
P. denticulata
 Primula seibodii comes from Japan and is also quite popular and quite a diverse species. Flowers can look like typical primrose flowers or be really finely divided and range from white to magenta to purple. This species likes plenty of organic matter and seems to like being consistently moist all season. If it gets too hot or too dry it will go dormant in summer, but usually emerges again in fall. Like other primroses, despite wanting consistent moisture during active growth, it needs well-drained soil to avoid rotting during dormancy.

P. sieboldii

P. sieboldii
P. sieboldii 'Petticoat Junction'

P. sieboldii 'Petticoat Junction'
Primula japonica falls under the candelabra group of primroses. The candelabras tend to have taller flower stems with whorls of flowers at the top and along the stem. They like similar conditions to the P. sieboldii: organic rich soil that stays consistently moist in summer. P. japonica is easy to grow in these conditions and will happily seed around creating a nice colony. Flowers tend to be magenta, but can also be found in red, white, and light pink shades.

A red form of P. japonica

Several other candelabra primroses are popular and readily available including P. beesiana with its pink to lavender flowers; P. bulleyana which features gold to orange flowers; and a slew of hybrids involving P. bulleyana, P. beesiana, P. cockburniana, and P. pulverulenta.

The alpine primroses are another popular group and includes several species and hybrids. The one most popularly available at retailers is Primula x pubescens, which is a hybrid involving P. auricula and P. hirsuta. This group also includes the Auriculas, which are border and show primroses that are some of the most popular plants among Primula enthusiasts. 

The alpine types tend to have leaves that are much more fleshy than other types of primrose. Like other types they are heavy feeders and appreciate plenty of organic matter, afternoon shade, and consistent moisture. But having alpine origins they also really appreciate well-drained soil. These are best suited to rock gardens and raised beds with some sort of gritty soil mix. I didn't have good success with P. x pubescens until I planted it in a bed that was about 50% crushed granite, 25% soil, and 25% organic matter. I also had a plant tight up against a large silver maple. The ground was raised around the root flair and the soil drained quickly there and that plant also did really well.

P. x pubescens

P. x pubescens
Hopefully some of the above information will help you out if you've never grown Primula or if you've struggled with them in the past. If you enjoy growing primroses and aren't yet a member, consider joining the American Primrose Society

Thursday, February 2, 2017

Garden Gems: Geum

Chicago Botanic Garden has released another plant evaluation report, this time for the lovely plants in the genus Geum. If you've never heard of this group of plants, that isn't surprising and you're not alone; they aren't terribly popular. 

I don't know that anyone can adequately answer the question of why they aren't more popular. They are easy to grow in average soil, as long as it isn't too wet in winter or too dry in summer. They bloom prolifically in mid-late spring (and in some cases continuing into July) and bridge the gap between spring bulbs and early summer flowers beautifully. The flowers come in a range of bright colors: white, yellow, pink, orange, and red. And they don't have many pest or disease issues. 

Thanks to the breeding work of Brent Horvath, owner of Intrinsic Perennial Gardens, that is starting to change. If you have discovered Geum recently, it's probably due to his "Cocktail" series of plants. I've been fortunate to see all of Brent's introductions and much of his breeding material during my visits to Intrinsic.                                                                                                                                                                                     One mark against Geum is that they're thought to be short-lived and require frequent division to thrive. This is certainly true about chiloense and coccineum hybrids like 'Mrs. Bradshaw' or 'Blazing Sunset' which are descended from species from Chile, Western Asia, and Southern Europe. But hybrids derived from other species can be as long-lived as any other perennial.  
      A mix of Cocktail series Geum

You can find the full report by clicking here and there's an earlier article here. Both are worth reading.
My interpretation of this report:
To me, this was a great trial. 49 varieties were tested and 46 completed the trial. Even some species that aren't readily available or thought of as garden plants were tested. Geum ‘Feuerball’, G. ‘Lady Stratheden’ and G. quellyon ‘Double Bloody Mary’ died out in the first winter and weren't re-tested and aren't included in the results. From the 46 remaining, the chiloense and coccineum types that you're likely to have trouble with only got 2 stars because they suffered dieback or died completely during the trial. It's worth noting that if you're in a warmer climate, these varieties may do quite well for you and are worth a try. But if you're in a cold winter area, it's probably best to avoid them. 

Varieties marked with 3 stars maybe grew well but didn't flower as well as others. Or they developed some foliage browning in summer. Maybe they suffered minimal dieback in winter. They're good plants, if you can't find any others that scored better, they're more than suitable for the garden. They may perform well in different circumstances. I've seen or grown some of the Cocktail series that got 3 stars and I was really happy with what I saw. 

Geum 'Banana Daiquiri' & Phlox pilosa 'Bungalow Blue'
Only 15 varieties scored 2 or 3 stars. That means 31 varieties, 67% of the varieties trialed, got 4 or 5 stars in this trial. Not bad for an unknown group of plants! Only 3 varieties received 5 stars, and they're probably among my favorites. 'Sangria', 'Totally Tangerine', and G. triflorum.

One thing you'll notice is that ‘Feuerball’ and 'Fireball' are listed. Despite ‘Feuerball’ being German for "fireball", these are different plants. ‘Feuerball’ is a dark red double and 'Fireball' is a bright orange double. 'Fireball' got 4 stars and is a good plant for cold regions. ‘Feuerball’ didn't survive the first year. 
Geum 'Fireball'
I grew 'Eos' when it first came out. It scored 3 stars in the trial for having some leaf scorch during summer and having poor flower production. The gold foliage turns green during summer. My experience was exactly the same as the trial. But it was the first variety with gold foliage. It's no longer on the market. Terra Nova has since introduced 'Sunkissed Lime' which is supposedly more scorch resistant and has much better flower production on taller stems. Flowers are also brighter orange. I have not yet grown this one, but I intend to pick it up soon to try out. 
Geum 'Eos'

Geum 'Sunkissed Lime'
 Probably my favorite variety of Geum is 'Totally Tangerine', which is also sold as 'Tim's Tangerine'. I've held the belief that this is one of the best since it was introduced. One of the tallest varieties at 24-30" in flower, I've always enjoyed the hot orange of this plant in late spring and into early summer. The flowers are at least partially sterile so it does bloom for a long time. Even when conditions weren't optimal, this one put on a good bloom show for me.

'Totally Tangerine'

'Totally Tangerine'

'Totally Tangerine'

'Totally Tangerine' in the back with Geranium psilostemon in front
I haven't grown many other Geum, mostly due to lack of availability. I will be picking up many more once I have a place to garden again. We may add some to the catalog in the future as well. Do yourself a favor and pick up a few. You'll be happy you did!

Wednesday, January 4, 2017

Thug Life: Mildew Resistance and Garden Suitability of Bee Balm

Mt. Cuba Center just released their evaluation of Monarda. So I thought I'd talk about it, Chicago Botanic Garden's 1998 trial, and my experience growing various forms. This will be a less image intense post than some of my more recent ones. Despite growing a number of Monarda through the years, I apparently haven't taken pics of many of them. I make up for the lack of pics with wordiness. Sorry peeps, this one is long.

Bee balm has been a popular plant for a long time. Centuries actually, it was grown in the late 1700s in Europe as a garden plant. Before that it was used medicinally by Native Americans and as tea by the American colonies. So it's no surprise that it's a staple of perennial gardens throughout the world. It's hardy, easy to grow, and easy to propagate.

Like many other Americans, Monarda had to travel to Europe to find itself. European breeders focused on Monarda didyma and Monarda fistulosa and bred them to create many selections and hybrids in an array of colors with large flowers. What they didn't focus on was disease resistance. If you've grown bee balm, you know what powdery mildew is and what it can do.

Monarda had to come back to America before selection for disease resistance would take place. It started at Morden Research Center in Manitoba, Canada with 'Marshall's Delight', Grand Marshall ('AChall'), Grand Parade ('ACrade'), Grand Mum ('MCmum'), and 'Coral Reef'. More recently other breeders (Walter's Gardens, Ball Horticulture, and others) have also focused on compact habit.

Thug life. Monarda can be a thug in the garden. Especially if you haven't grown it or a new variety exceeds your expectations of vigor. Monarda didyma and its hybrids are highly rhizomatous. They can take up a good chunk of garden real estate. This habit can also make it quite dense which exacerbates the mildew problems it can have. Plan on giving it space, dividing it every few years, and thinning stems out to promote good air circulation. Easy to grow, yes; low maintenance, no. Worth it.

Besides promoting good air circulation, there are several other cultural considerations for reducing mildew. While tolerant of a wide range of soils and conditions and highly drought tolerant, excess moisture or extreme drought will lead to mildew susceptibility. Also, clean up old stems and foliage as completely as possible. Mildew overwinters on leaf litter and in soil. If you have a serious mildew problem, you can use several fungicides to good effect. My preferences are organic fungicides like copper and Green Cure. Actinovate can also be used as a foliar spray for prevention of mildew.

Being that bee balm is a garden staple and I've been in the horticulture industry for 20 years, I've grown A LOT of it. Many I've only grown as a container crop for sale but I've grown quite a few in gardens as well. I haven't found a greater susceptibility to disease when growing in containers, and no variety is 100% mildew free. Both Mt. Cuba and Chicago Botanic rated plants based on disease resistance, habit, flower coverage, and bloom time; and for the most part their results match pretty well.

One glaring exception is 'Marshall's Delight'. Chicago found it "had the lowest level of infection with no more than 5% ever observed" while it ranked almost at the bottom of 40 varieties at Mt. Cuba "due to severe powdery mildew infections that caused significant damage and defoliation by midsummer." This could be attributed to regional differences. But my experience in gardens and containers has matched up very well to Mt. Cuba's findings. This is one of the least mildew resistant plants out there. I've tried it several times and it's always been awful.

Another exception is Monarda fistulosa 'Claire Grace'. Chicago rated it a 2 and Mt. Cuba gave it their highest rating of 4.5 for "its sturdy, upright habit and prolific floral display." They rated its mildew resistance as good. I have not tried this one yet, but will pick it up to compare it to straight Monarda fistulosa which also has excellent habit but terrible mildew resistance. On the topic of M. fistulosa, forma albescens (often sold as 'Alba') scored ok in Chicago's trial with 3 stars and a good resistance rating. There aren't a lot of white bee balms and most are very susceptible to mildew.

Red bee balms are always popular and often the worst spreaders and most susceptible to mildew. Both trials rated 'Gardenview Scarlet', 'Colrain Red', and 'Raspberry Wine' very highly. Mt. Cuba also scored 'Jacob Cline' a 4.0. I've had mildew to the same extent on 'Jacob Cline' and 'Gardenview Scarlet' and it wasn't too bad. Both had a looser very spreading habit for me. 'Colrain Red' I've only had as a container crop and only once for a short time as it sold out very quickly. 'Raspberry Wine' probably wins the award for most vigorous of all the ones I've grown. My plant quickly grew to nearly 5' tall and 10' wide. It was removed from the gardens for being too vigorous as I didn't have the space for it. Despite this vigor it was very dense, had almost no mildew, and is still a favorite of mine for color. I will be putting it in the new gardens and giving it ample space.

'Raspberry Wine' in year 2
'Raspberry Wine' in year 3. 5' tall x 6' wide. This plant was removed a year later.
'Raspberry Wine' in year 3. 5' tall. 

A close second place in the vigor category for me is 'Purple Rooster'; it's slightly less vigorous and dense than 'Raspberry Wine'. It also ranks very highly in the color category for me as it's the only true dark purple I've seen. This was selected from a batch of seedlings at The Flower Factory here in Wisconsin. It is also very mildew resistant. Mt. Cuba ranked it a 4.1.

'Prairie Gypsy' is a hybrid of M. bradburiana and scored a 3.8 at Mt. Cuba. They rated its mildew resistance as fair. I have grown this, actually in a quite shady spot, and not had any mildew issues on it. I will concur that it has a lax habit after bloom. Even after moving to the sun, the floppy habit persisted. I like this one regardless. Bloom time is intermediate between M. bradburiana and M. didyma, usually in bloom mid-June.

Best picture I could do of 'Prairie Gypsy'

'Peter's Purple' is a hybrid of M. fistulosa 'Claire Grace' and the Mexican species M. bartletti. It is usually listed as being zone 6 hardy and that's probably the safest cold zone for it. I did grow it for a couple of years though and it did ok until we had a very wet winter. So it may be doable in zone 5 with proper drainage and planting early in the season. Mt. Cuba rated it 3.7 based on fair mildew resistance and a spindly floppy habit. Mildew resistance for me was ok, mostly the lower leaves were affected. Spindly? Yes. It never filled out well and wasn't very dense. Floppy? No. The stems were quite sturdy. Much sturdier than the average bee balm. Flower color is dark lavender.

Grand Marshall ('AChall') was the highest scoring compact variety from Mt. Cuba. They say "its growth habit is still Monarda-like, growing in a uniform mass that spreads slowly outward. Many of the newest compact selections are dwarfed to the point of looking artificial and out of place in the landscape. The habit of Grand Marshall™ habit better lends itself to blending with its neighbors in an attractive and natural way." So far, I have to concur. Grand Marshall has been one of the best performing bee balms I've grown. Almost no mildew, fuschia-purple flowers, and compact and slowly spreading but still a good grower. This is the standard by which I judge all other compact Monarda, and so far none measure up.

Grand Marshall on the left looking very pink. 'Raspberry Wine' on the opposite end.

Grand Marshall after being moved to the new garden. This color is much more correct. 

So what about those other compact hybrids? Let's start with other Morden selections. Grand Parade ('ACrade') wasn't too bad, it's almost as good as Grand Marshall. Mildew resistance is excellent. Vigor is quite good, like Grand Marshall. Habit is not as good, tends to hollow out in the center quickly. Mt. Cuba found that to be the case as well.

 'Petite Delight' scored in the middle 3s (3.4 and 3.5) in both trials. It shows reduced vigor and is slow to establish. Mildew resistance is good. It suffers from low flower coverage and very short peak bloom.

'Petite Wonder' might just be one of the worst varieties ever introduced. It scored near the bottom of Mt. Cuba's trial with a meager 2.7. I think they pretty much cover it: "Monarda ‘Petite Wonder’ is one of the worst performing cultivars in our trial. The plants hardly grew over the three year period and both its floral display and powdery mildew resistance were mediocre. In fact, there was no other cultivar that displayed such a significant lack of vigor."

'Coral Reef' I have not grown in the garden. But it had a lack of vigor in container culture. Flower color is a strong medium pink and is quite nice. Mildew resistance is good. Flower coverage is below average. Mt. Cuba had issues with some sections dying out over winter. Based on the lack of vigor I experienced in container culture, I guessed that the 36-42" advertised mature height was unlikely. Mt. Cuba seems to have confirmed this as their plants only grew to 20".

Neither trial covered Grand Mum ('MCmum'). I only grew it once as a container crop. The mildew susceptibility I encountered in container culture convinced me that I never wanted to put it in anyone's garden.

Continuing in the tradition of other European introductions, the Lace series ('Pink Lace' and 'Cranberry Lace') have only fair mildew resistance. Mt. Cuba had trouble with 'Cranberry Lace' overwintering and attributed it to defoliation from mildew. I have also had trouble overwintering the lace series, but I didn't have significant defoliation problems. Flower color on both is excellent, but I guess not worth the trouble.

'Balmy Purple' received a low rating of 2.7. Mildew resistance was fair, habit was irregular, flowers were large, bloom time was short, and vigor was low. All the basic traits of a compact Monarda. In containers the mildew resistance seems good.

'Pardon My Pink' and 'Pardon My Purple' both got low marks, 3.1 and 2.6 respectively. Typical complaints about compact Monarda apply here. Though I didn't have any issues with mildew in pots or in the garden. The colors are really quite good and an improvement over some older varieties.

Species etc in the trials:
Monarda clinopodia and Monarda 'Bryan Thompson': These two plants are apparently remarkably similar. I don't fully agree with Mt. Cuba's logic that "‘Bryan Thompson’ is unlikely to be M. clinopodia because the species does not grow in Texas where ‘Bryan Thompson’ was discovered" without knowing more about the area and the collection. Plants escape cultivation, though M. clinopodia isn't exactly widely grown. so I guess it's just as likely to be an undescribed species. I'd really like to pick both up and compare them and maybe try to key them out and see what happens. In any case they both seem to be decent plants. They only scored low due to unkempt habit. Mildew resistance was excellent. White flowers. Worth breeding with.

Monarda austroappalachiana 'Snowbird' received low marks for all of the typical complaints associated with compact hybrids. Except mildew resistance, that was excellent. Another white flowered thing worth using in a breeding program.

Monarda bradburiana is another compact species with great mildew resistance but a floppy habit. I concur with Mt. Cuba: "If further research of this species focuses on sturdier habits it would easily be one of the best bee balms for garden use." Fortunately, this is happening. More about this shortly.

Monarda citriodora and M. citriodora 'Bergamo' both scored low for floppy habit. 'Bergamo' was the worse of the two in this regard. This is an annual species that can self seed in gardens. Flowers are stacked. A neat plant, but goes dormant early. Excellent mildew resistance.

Monarda punctata scored quite high, a 4.0. This is another species with a stacked inflorescence. The flowers themselves are yellowish with brown spots and not terribly attractive. The bracts surrounding the flower however range from white to pale yellow or light pink and are incredibly beautiful. This species is a tough one to grow and requires very well drained soils. Here in Wisconsin it is found on sand dunes along Lake Michigan. It's been said to be annual, biennial, and perennial. I've always leaned towards biennial as that was my experience but Mt. Cuba found it reliably perennial. Chicago had all plants die in the first winter. It can look pretty rough later in the season as it defoliates after flowering. Lots of potential for selection. Added bonus is that it's one of the most attractive to pollinators. Especially predatory wasps.

New things not in the trial:
Monarda 'It’s Majic' – "Most likely a hybrid of fistulosa and didyma. These extra vigorous  plants reach 5’ tall. Dark foliage and some purple stems add interest too. Bright  purple flowers are super eye catching and last an extra long time blooming in  summer."  From Intrinsic Perennial Gardens. We got a few of these for sale this past year. I liked the foliage, form, and flowers. They did get some mildew in pots though. Unsure how resistant it will be in the garden.

The Leading Lady series is a pair of plants from Walter's Gardens that are hybrids of M. bradburiana. Supposedly densely branched, that may solve the floppy habit problem. 'Leading Lady Lilac' is lilac-lavender and 'Leading Lady Plum' is more typical purple. Flower time is late June and habit is compact. We'll see how vigorous they are.

The Sugar Buzz series has been around for awhile, includes 8 varieties, and I'm surprised none were in the Mt. Cuba trial. Also from Walter's Gardens, this is another compact series. I have not grown them, but mildew resistance is apparently quite good. Not sure about vigor.

There are also further plants in the Balmy series and Pardon My series, though I expect them to be similar to those already trialed.

Monarda 'Balmy Lilac'

Monarda 'Balmy Pink'

Despite all of the problems associated with Monarda and mildew, it has continued to be a garden staple. That tells me that people are willing to overlook spreading habits, ugly foliage, and lack of vigor in the case of compact varieties. While we focus on the flowers of these plants, much can be said about the fragrance of the foliage too. It's a welcome addition to the garden. There is much improvement that can be done to this group of plants, and we've really only started to branch out beyond M. didyma and M. fistulosa. I've often thought about working with them, and may yet do so. Much of the focus is on compact habit, but I think tall varieties are the way to go. Especially restraining vigor of some of the big plants and getting a good white flower. And of course continued improvement of mildew resistance.

Wednesday, December 7, 2016

Chicago Botanic Gardens Part 3: The Trial Garden

Finally to part three of our Chicago Botanic Garden trip! This is one of the few trial gardens in the country dedicated primarily to perennial plants. 2016 saw their first non-hardy plant trial, Salvia, which I pretty much covered in Part 1. We did not see all of the current trials and I didn't take pictures of all of the trials we did see. I wish I had, but these trials go on for several years so it's a good excuse to return in 2017. From the trial garden website: In all, 20 comparative trials are currently underway including "Andropogon (bluestem), Asclepias (milkweed), Baptisia (false indigo), Chrysanthemum (hardy mum), Coreopsis (tickseed), Filipendula (meadowsweet), Hamamelis (witch hazel), Heliopsis (heliopsis), Hibiscus (rose mallow), Hydrangea paniculata (panicle hydrangea), Hydrangea serrata (Japanese hydrangea), Lespedeza (bush clover), Molinia (purple moor grass), Perovskia (Russian age), Persicaria (smartweed), Potentilla (perennial cinquefoil), Rosa (English shrub roses), Salvia (hardy and non-hardy sage), Schizachyrium (little bluestem), and Weigela." 

Beyond this list there were several plants that were in the trial garden area from previous trials or smaller trials of only 2 or 3 species. 

The Hibiscus trial was nice looking, and it's needed due to the ridiculous number of varieties coming onto the market. They all seem like great looking varieties, so how do you choose which ones to buy? 

The Perovskia trial looks like it was just started and NONE of the plants looked great. I didn't take any pictures. I really look forward to seeing them again in 2 or 3 years as there are a lot of new varieties that all promise they are compact. We've heard that before.  
 As you can see from the list, several grasses are being trialed.

Andropogon 'Rain Dance' was one of the nicest of the group when we visited. I'm also very fond of its siblings 'Red October' and 'Indian Warrior'; all from Brent Horvath of Intrinsic Perennial Gardens.

I was very happy to see a Molinia trial. These grasses are fantastic and far under-used and under-valued. Many of them are very tall but even with heavy plume production offer some transparency. Great for creating some interesting views. 'Karl Foerster' was the tallest and probably my favorite of them. But all were quite nice and very usable in garden design.

Molinia 'Fontane'
Molinia caerulea ssp. arundinacea ‘Karl Foerster’
Molinia 'Whirlygig' 
R-L (If I remember correctly) Molinia caerulea 'Variegata', 'Fontane', 'Karl Foerster', 'Whirlygig'.  

Panicum 'Bad Hair Day', this was labeled as a Chicagoland Grows plant; I want it SO BAD! Fitting name and look at that flower coverage! 
Schizachyrium 'Standing Ovation' was looking great in the trial. One on my wish list. 
Sorghastrum 'St. Louis' is another intro from Brent Horvath. I had this and need to replace it as it didn't survive being moved. The center plants looked great, the end plants were lodging a bit. Very tall, over 6'. Should develop nice fall color.
Baptisia 'Blonde Bomshell' was looking a little rough this late in the year, but look at those old flower spikes. GREAT coverage on a compact plant. 
Coreopsis tripteris. A 6' coreopsis that looked great, though it was mostly done blooming. 
Eupatorium fortunei 'Pink Frost' was looking great. Nice variegation and a good performer. 
Hydrangea paniculata 'Mega Pearl' was past prime color, but it had GREAT habit and coverage. 
Hydrangea paniculata 'White Lady' also had great habit and coverage. 
Kniphoffia trial. Very much needed, these plants can perform great into z5 if proper drainage is provided. 

Lespedeza was another ongoing trial that I was very happy to see. Another under-used but really great group of plants for fall flower color. Some of these were quite compact, but I'm not sure if that's because they're young or because they're actually compact. I look forward to reading the published notes in a few years when this trial is complete.

Lespedeza thunbergii 'Gibralter'; if you find a Lespedeza in a garden center, it will likely be 'Gibralter'. This is the most common one and it's a good plant. 
Lespedeza thunbergii 'Gibralter'
Lespedeza 'Spring Grove'
Lespedeza 'Summer Beauty' 
Lespedeza 'White Fountain'

I didn't get the tag on this one, but it shows how great the genus can look. 
They had several Pycnanthemum on trial. Another under-used group of plants. They will probably never be popular, but they are good utilitarian filler plants that can be very drought tolerant. Also, bees and butterflies tend to love them. They were past peak, but these two I'd be happy to include in my gardens as the habits were quite nice.

Pycnanthemum incanum
Pycnanthemum tenuifolium 'Cat Springs'
 The mum trial was somewhat unimpressive, though in all fairness I don't like mums all that much. I did take photos of these two as they were in excellent shape and had nice bloom.

Chrysanthemum 'Bolero' is a fairly reliable perennial mum with good orange color.
Chrysanthemum 'Country Girl'. This is similar to 'Clara Curtis' or 'Frans', but with maybe larger flowers. Certainly in bloom earlier than 'Fans', but that could because this was 150 miles south of me.
 We really enjoyed our trip to Chicago, 10+ years is far too long between visits and I hope to return much sooner next time!