Tuesday, July 27, 2010

Garden Designers Roundtable: Underutilized Plants, or Forget-Me-Not!

Today, as part of the Garden Designers Roundtable monthly garden design discussion, I’m focusing on underutilized plants.  I’ve chosen to highlight a few plants from my xeric meadow garden: USDA zone 5, altitude approximately 5,350’, sandy-loam soil, full sun.

Caragana microphylla, littleleaf peashrub
Peashrubs are often dismissed as being uninteresting or worthless.  Not true!  This mass planting along the east property line of my back yard serves as a backdrop to my meadow garden and creates a subtle screen to the neighbor’s property.  The very fine texture makes an interesting contrast to their bulk; these shrubs are 8-9’ tall and 4-5’ wide, but don’t feel heavy or imposing.  They are like a lace curtain – allowing for air movement and light play - rather than a brick wall!

Pale yellow, pea-like flowers cover the plants in late spring, just as the delicate, pinnate leaves emerge.

Note, too, the silver “wire work” tracing along the smooth, olive colored branches; a lovely detail to discover.

Caragana microphylla are fast growing, sun loving, xeric, and tough---no snow load damage problems here!  Plant with bold foliage companions such as Helianthus maximiliana, Verbascum bombiciferum, Yucca sp., Callirhoe involucrate, or …

Phlomis cashmeriana, Kashmir sage
This bold, architectural perennial is fairly new on the garden scene (introduced by Panayoti Kelaidis of Denver Botanic Gardens), and is the perfect addition to any xeric garden.  The soft, lavender- pink flowers appear in whorled clusters on tall spikes in very late spring, and last for several weeks. 

The large, basal rosette of foliage is especially interesting: a net-like texture covers the surface and the edges are strongly serrated.

In my dry, sunny, meadow garden, this plant will bloom out at 4-5 feet tall, but in one of my other planting beds that gets afternoon shade, it tops out at about 2 ½ feet. Companion plants for Kashmir sage might include Cytisus purgans Spanish Gold®, Delosperma nubigenum, and Agastache sp.

Dalea purpureum, purple prairie clover
This is a beauty.  Long blooming “rods” of vibrant, red-violet flowers offer a bold contrast to the delicate, lacy foliage.

Many xeric plants feature soft, gray-green or silver foliage; purple prairie clover’s is a refreshing, deep blue-green.  My plants form an upright, rounded silhouette, about 20” tall and wide.

By the way, purple prairie clover is a deep rooted legume that adds nitrogen to the soil---an ideal way to add fertility to a naturalized garden area.  Plant it with Artemisia frigida, Helictotrichon sempervirens, Tradescantia occidentalis, and Mirabilis multiflorus.

All of these plants are a bit unusual (though not impossible to purchase locally) and I rarely see them featured in the private gardens that I visit here in the Denver area.  Be the first on your block to give them a try!


Debbie/GardenofPossibilities said...

Jocelyn, I've found a few plants here that I will have to try in my garden, Kashmir sage being tops on the list. I love photo of your litteleaf peashrub hedge and the analogy of it looking like a lace curtain, it is so true.

Jocelyn H. Chilvers said...

Thanks, Debbie. I'll look forward to seeing what companion plants you choose for the sage!

Andrew said...

Kashmir sage gets to 4 or 5 feet? Wow! I planted out some plugs from a liner tray I got for free last year, and they haven't grow much, but they're still hanging in there. I'll be looking forward to that.

Great points about pea shrub! I've been interested in getting my hands on a cultivar called 'Mongolian Silver Spires,' but it was introduced by the Nebraska Statewide Arboretum and hasn't made it east yet.

Jocelyn H. Chilvers said...

Andrew, I wish I could tell you the name of the caragana cultivar I have, but I planted them about eight years ago and have totally forgotten what it is. Size-wise it is similar to the 'Mongolian Silver Spires' as opposed to 'Tidy' which will grow 10-12' wide. Thanks for stopping by!

Genevieve said...

Oh I love love LOVE the pea shrubs! Thanks for promoting them Jocelyn, for all of their resilience, texture and form! They seem to just embody our landscape's western spirit.

I'm looking forward to mass planting pygmies in a street median next spring and have truly enjoyed the weeping form we planted last summer.

I love your contributions:) Keep them coming!

Susan aka Miss R said...

Of the plants you contributed I only know one--the Phlomis ssp. which does fine here...I was hoping someone would include it! How do the others take our eastern humidity? Often that's a forgotten aspect when choosing a plant...so many just can't handle it.

Laura Livengood Schaub said...

Another vote for the pea shrub; I wonder if it's evergreen in warmer zones? Will definitely check it out, so pretty and lacy. Love seeing your meadow!

Anonymous said...

Lovely choices. I particularly like the Caragana for tall but not impenetrable screening and will remember that for use in the future!
And I loved the stem detail. Details like that are the icing on the cake with some plants!
Great, subtle plantsmanship, Jocelyn!

Jocelyn H. Chilvers said...

Genevieve---glad to hear you'll be using the caragana as a street planting; sounds like a perfect choice for a tough, lush-looking planting!

Susan, I'm not sure how tolerant Phlomis are when it comes to humidity. Certainly, a site with well drained soil will help. The humidity issue is one of my pet peeves---for the opposite reason! Many Zone 5 plants that thrive in the Northeast just cannot tolerate the low humidity here. Zone (cold) tolerance is just the starting off point re: plant adaptation!

Laura, your question about the caragana's evergreen capability has piqued my interest. I'll let you know what I find out!

Robert, I'm with you on the details. Showy can be fun, but the quiet details keep pulling us in. (Kinda like people, eh?)

Thanks, all, for visiting The Art Garden today!

Les said...

I got some great shots of Dalea at the Denver Bot. Garden last year. I had never seen it before and it was covered with honeybees awaiting their close up.

rebecca sweet said...

I must definitely find some of that gorgeous prairie clover - I don't think I've ever seen that! Beautiful photos, too - thanks!

Pam/Digging said...

Yum! After starting off with the northeastern and northwestern contributors and their luscious, acid-loving plants, now I'm seeing some dry-land beauties I can more likely grow. I love your "lace curtain" between you and the neighbors, and I'm especially intrigued by that Phlomis. I grow P. fruticosa and would love to try this variety as well.

Denise said...

The dalea is now officially on my fall planting list. Great plant portraits.

Jocelyn H. Chilvers said...

Les, I noticed that stand of Dalea at DBG when I was there a couple of weeks ago. It really pops against the buffalo/blue gramma grass meadow there. My meadow garden has a base planting of buffalo grass (Bucheloe dactyloides) too.

Rebecca, Denise, and all: an online source for the Dalea is http://www.highcountrygardens.com

Pam, give the Phlomis a try! You and Susan C. can report back on its humidity tolerance. I regret not having a photo to show you of the full plant in bloom---I was *sure* I had one in my stash, but no luck. Next year!

Thanks for visiting!

Genevieve said...

I'm a fan of that Kashmir Sage, as we do a lovely job here on the coast with the yellow Phlomis. I hope our nurseries get it in soon as it looks like it'd go beautifully with some green pennisetum and other favorite plants.

Jocelyn H. Chilvers said...

Yes, Genevieve, the soft flower color and bold foliage make it a great mixer with lots plants---I love your idea of the pennesetum!

ScottHokunson said...

Could it be that the Caragana, is a substitute for our invasive Eleagnus? That would be a nice treat! The Phlomis and Dalea are also on my list of plants to try, especially the Dalea. Love the habit and blossom shape. Thanks for the companion suggestions also!

Jocelyn H. Chilvers said...

I think the Caragana would do well in your region, but not so sure about the other two (unknown humidity tolerance). Hope you'll give them a try and let me know how they do. I think you are the first person to comment on the companion plant suggestions, so bonus points for you, pal!