Great list. A couple others:

- Epimedium
- for grasses, Deschampsia and Molinia

rehmannia alata, aka chinese foxgloves - long flowering, unusual and exotic
dierama pulcherrimum or angle's fishing wands (was briefly obsessed by these)
indigofera heterantha - a woody shrub which dies back to the ground, but always returns - gorgeous airy legume type flowers - for those terrified of wisteria
incarvillea delavayii - a white form (snowtop) drought resistant and lovely
rhodochiton atrosanguineas - a clinging climber and terrific companion to thunbergia alata
omphalodes verna - another delightful spring ephemeral (with an annual form, easily direct sown - omphalodes linifolia
linum campanulatum - oddly named tree flax, despite the fact it is only 5inches with golden bell flowers
seselli wallichianum - could go an at length about umbellifers - probably this years favourite genus (see also chaerophyllum hirsutum and pimpinella roseus)
glaucidium palmata (trilliums getting too fashionable? try glaucidium, in either lilac or white)
aconitum - either early lycopodium or the later blues such as carmichaelii or napellus (get that delphinium type fix with less snail munching and at a really welcome time of year.
anthericum liliago - a great companion to camassias with white spikes of graceful flowers (think it is also known as St.Bernard's lily)
althea cannabina - an enormous (but airy) substitute for the ubiquitous verbena bonariensis
schizostylis coccinea - another favourite from some years ago (unfortunately, my soil was too dry for them to thrive)
Papaver rupifragum - many interesting poppies with lovely foliage....and far easier than struggling with the irritable meconops.
would also like to see a revival of lathyrus - there are many good plants in this genus (currently growing vernus, nervosa, tingintanus and sativum)

I have avoided mentioning alpines as for some reason, these plants have failed to gain much traction in the US - at least the alpine forum is utterly moribund.

These are semi-recent & (thus far) much-appreciated additions to my various perennial beds.

Alchemilla mollis (Lady's Mantle)
Hellebore (Lenten Rose)
Persicaria virginiana (Fleeceflower)
Polemonium (Jacob's Ladder)
Trollius (Chinese globeflower)

The Lenten roses need a year or two before they take off but once they do, the show is early, spectacular & definitely worth the wait. In my experience, all have season-long attractive foliage & require little to no care or maintenance. I grew the fleeceflower, Jacob's Ladder & globeflower from seed via winter sowing.

Astrantia, definitely
I second Globeflower, I have Chedder and it's coming along nicely.
Bloody Sorrel!
I think all Anemones are underused. Almost never see them at the local nursery or big boxed stores and they are such showboats!

I know technically not perennial, but I think Cerinthe major purpurascens is one of the most underused plants, period. It is so spectacular, both in foilage and bloom, especially Blue Honeywort, because of it's blue coloring. Starts blooming early and keeps going like the energizer bunny. Adds so much texture and appeal to any garden. Nothing else like this plant!

This is a pic of Blue Honeywort's growth so far this year. Well, technically it is a perennial in New Zealand, at the very least!

Here is a closeup of the blooms. For anyone unfamiliar with this plant, the blooms get much bigger and the leaves surrounding them just get bluer and bluer and layer even more. So cool!

Nice cerinthe, I always assumed it wouldn't do well here and I guess that was wrong!
Campanula- you put together a wish list of plants that either hate the hot summers around here or refuse to deal with the cold and ice of winter.... Except for the lathyrus, I'm having a little luck with some of them.

I'd also like to see more of these in gardens and garden centers:
Epimediums, martagon lilies, (love) hosta plantaginea, hardy cyclamen, daylilies with nice foliage in August!, "isla gold" tansy....

Does anyone have an idea why Madonna lilies aren't more common? Are they too old fashioned or just hard to grow?

Ah yes, I forget how temperate the UK is - we moan about our cool and fleeting summers while we grind to a halt with 6inches of snow but it truly is horticultural heaven. I am always a bit shocked by the extremes of US weather.
So, will try harder with:
delphinium zalill - I grew these by mistake and was utterly thrilled by the pale yellow spike of delicate delph blooms - not being a massive fan of those giant blue columns, this bone hardy delph was a joy - enough to get me curious about D.nudicaule.
Verbascum phoeniceum - these have been in and out of style for a few years, with numerous varieties, both tall and dwarf....but I am still very fond of the smallish 'violetta' - a more graceful variety which flowers early June, then again in late summer. Never seems to attract the attentions of the pernicious mullein moth caterpillars either.
Linaria purpurea - I expect some head-shaking since this is a weed in many people's eyes but I grow the softly pink 'Canon Went' - a joy even when not in flower since the glaucous foliage is always neat and attractive. The common purple looks neat with golden yellow welsh poppies (meconopsis cambrica)
Campanula collina - had to go for one of my favourites...and I think this is even one of yours (US) - but nonetheless, this medium sized bellflower has a good deep blue without the rampageous growth of lactiflora, the invasive attitude of takesima or the rank foliage of trachelium...and does not seed everywhere like persicifolia - altogether an underused but delightful plant.
I am also enjoying alstroemeria for the length of bloom and the lesser grown Phlox maculata - a more graceful variety than P.paniculata
Kirengoshoma palmata - a lovely plant at all stages of growth, culminating in creamy bell-shaped flowers in September - a woodland treasure.
Leucojum aestivum, verna or, the later (and tinier) autumnalis - for those of us who cannot get enough of snowdrops.
Millium effusum- Bowles Golden Grass - an easy from seed, grow anywhere flash of acid green.
Sidalcea - love the malva family, so I am also enamoured of various sphaeralceas, anisodonteas and, new to me this year, illiamna.

I think Delosperma should be used more because they are amazing and easy to grow. The period of bloom on them is very long and they are evergreen here too. They look great in hanging baskets or as a groundcover. They are also easily propagated!

Two for the part shade garden that people should consider more often are the blue monkshoods (aconitum) and the skullcaps (scutellaria). Both are pretty hardy and maybe the best from my viewpoint is deer don't like them. Monkshood in particular adds color and height August to November when the summer garden has often gone out of bloom.

I think most of the really cool unusual ones have been mentioned. Ispahan mentioned most of the ones I have in the garden (I especially love Anenome nemerosa) plus Skullcap by another above poster. I have a few of some of the cool violets around my place.

Not the weedy V. sororia but the following Violets: Viola canadensis (White), Viola striata (Cream Violet), Viola labradorica (Labrador Violet), Viola pedatifida (Prairie Violet)

Dragonhead, Dracocephalum tanguticum
Indian Pinks, Spigelia marilandica
Aromatic Aster, Symphyotrichum oblongifolium
Bowman's Root, Gillenia trifoliata

Just to add a few more.

Karen

Campanula, you listed many of my favorites. So did several others.......

I used to post here many years ago, but since developing Rheumatoid Arthritis, I'm a much more sporadic gardener, and I haven't posted in a looong time. I do get a lot of pleasure out of reading all about some of the gardening antics of y'all here, though ! :-)

This post was edited by giraffe on Thu, May 9, 13 at 12:17

Here are several I'd like to see in the States:

Fritillaria imperialis - nowhere to be seen
Campanula - seeds came from a friend in British Columbia
Helebores - no promotion
Heleniums - none to be found in the States, ironically
Wallflowers - we only have the orange variety

I would love to have these in my garden!

I don't know where you're searching, sweetannie, but you shouldn't have any problem finding those plants on line. I found them in a few moments.

I hope you do not mean Polemonium caeruleum(if yes, then you're obviously not aware what you're asking for).

I found Glaucidium palmatum not particularly long-lived here, especially the white ones;had hundreds of seedlings, they are all gone, don't know where to.

Alchemilla mollis underused?? Not here in Denmark; this is practically the only plant planted everywhere in public places.

Underused plants: Helianthus, Veronicastrums, Heleniums, Aster frikartii.

rhizo,

Thank you, but I do not order perennials or bulbs via on-line.
I go to real plant nurseries so I know what I am buying and don't have to pay an arm and a leg for my plants, plus shipping and taxes.

If the plants I listed above weren't so "underused" in gardens here, then local nurseries might start growing them to sell...and vice versa. Comes down to "Demand and Supply." rather than Supply and Demand. If enough people asked for them, the local nurseries would supply them.

The most overused garden flowers here:
Begonias
Marigolds
dwarf zinnias
dwarf red annual salvias,
and dwarf everything else.
-------------------------------------

wieslaw59,
Alchemilla mollis is terribly underused here in most areas of the States.

The problem here is that garden centers and even nurseries do not make as much money from perennials as they do annuals and tender perennials. Annuals have to be replaced every season and every year, and sometimes several times during the growing season if the weather does damage. Also, if they lose most of the inventory, it is easy enough and much cheaper to replace with fast growing blooming annuals than perennials. People want to see "Instant" color and plants that don't have lots of colorful flowers are not going to sell.

Whereas, perennials return year after year and also reseed themselves. There is no big money to be made by selling long-lasting, self-seeding plants.

That may not be the only reason, but it is likely the main reason.

~Annie

Annie, no nursery, no matter how large, can carry all the magnificent perennials (or shrubs or trees for that matter) that are available in this country. You seriously limit yourself by not considering mail order. I mail order almost everything--and among the great perennials not yet mentioned in this post are:
Persicaria polymorpha
Persicaria 'Crimson Beauty'
Begonia grandis
Pardancandas
Saruma henryi
many unusual cultivars of Agastache and Salvia
Epimediums
Prairie Smoke (Latin name escapes me)
Silphiums

I could go on and on.

tepelus wrote:

Indian Pinks, Spigelia marilandica

I take it Karen you have no problem getting this plant to return each spring in your zone 5 climate? I planted two last year in relatively sheltered locations and neither made it through this past winter. They have such unique flowers...such a cool addition in a shady area of a garden. But twice bitten I am now gun shy of trying it again.

Rouge21:

I live on the border of 5 and 6, and I've had them come back for a couple of years now. They are slow to rise in the spring. I even had a stem break off when I first got the plants, pushed it in the soil in a pot and kept it watered, and it rooted. Might have been lucky, though.

Karen

They used to grow Fritillaria imperialis at Mt. Vernon here in northern Virginia. I have not been there in the summer in several years, so I am not sure they still have it now that they have redone the gardens.

They used to grow Fritillaria imperialis at Mt. Vernon here in northern Virginia. I have not been there in the summer in several years, so I am not sure they still have it now that they have redone the gardens.

So many wonderful plants are being mentioned here! I was even reminded of a few of my favorites that I forgot to include in my initial post--aconitum, silphium, trollius, etc. I was fortunate to be able to buy some tiny plugs of 'Isla Gold' tansy last summer. It quickly disappeared in the heat and drought and I thought it was dead. This spring, however, it has all come back and is quite sturdy and vigorous. The golden, ferny foliage is fresh and wonderful.

Rouge21, don't give up on your spigelia quite yet. Last year we had a significantly warmer spring than this year and my single clump of this plant did not begin to emerge until almost mid June. But I am not sure what this plant needs to thrive. When my clump finally began to grow, it had twice as many stems as the year before but produced no flowers.

Another group of plants I forgot to mention in my original post is primroses. Primula sieboldii cultivars and Primula kisoana are amazing for forming free-blooming carpets in woodland or shady areas.

In Southern California:

Rehmannia elata (Chinese foxglove) Pretty flowers, long bloom period, easy to grow and divide, spreads but easy to control. Then when it is finished blooming, it can be taken down to the tuft of foliage on the ground, making way for other plants. Until it sends up additional flower stalks.

Bletilla striata Yes I know it is an orchid, but it acts just like a garden perennial. Pretty purple, pink or white flowers that last for months. The foliage is attractive; some are slightly variegated. Quick growing and easy to divide, but not invasive. Super easy to grow. It even has a sense of humor--occasionally sending stems straight down, through the drainage holes of pots, without U-turning after their exit to correct their silliness.

Kalanchoe mirabilis Several plants seem to be sold under this name, but I like the short, shiny green leaved red tubular-flowered plant. It is neat and attractive. They flower at a time before most of the plants in the garden get rolling, then bloom for 4-5 months. Look nice out of bloom. Easy to grow and increase by sticking a branch in the dirt.

Lotus berthelotii (ParrotâÂÂs Beak) Yes, sometimes some of the foliage just freaks out and parts of the plantâÂÂs foliage takes on a scorched look, even though the rest of the plant or the neighboring plant, shows no damage. But when it blooms, which it can do for long periods, multiple times during the year, it is an attention grabber.

Bergenia Coarser leaves give a nice contrast in the garden, although they look better with regular old leaf clean-up. I have grown it in sun or shade. It flowers off and on all year. Tough, no-fuss plant.

Arenaria montana I love this plant. Nice green leaves, pretty white flowers. Short and neat. BUT it seems to hate SoCal heat. I buy the very rarely offered A. montana at the nursery, place it in a bright but mid-day sun-sheltered place in the garden, and fawn over the little patch until an some unusual weather pattern makes it call the whole thing off. Then I look for another. If more folks in SoCal would grow it, I wouldnâÂÂt have to search so hard. ;-)

ispahan wrote:

don't give up on your spigelia quite yet. Last year we had a significantly warmer spring than this year and my single clump of this plant did not begin to emerge until almost mid June.

Wow! Is that normal for this plant i.e. to emerge so very late? And so I take it your spigelia has not come up yet?

Great thread everyone. Thanks ispahan for starting it. I wonder if many of you. like myself, are "googling" these plants. For example I am intrigued by "Arenaria montana". Some descriptions show that it can take some 'good' shade. I will keep my eyes out for at least this plant in this list.

I wanted to touch on the local vs on-line purchasing issue again. I think it is very reasonable for those who have time and high quality nurseries nearby to save money and choose exactly the plants they want by shopping locally. However, the mail order companies do a wonderful job of packing and mailing excellent quality products. And they survive or fail depending on their customer service. If you receive anything you consider subpar they will replace it with no questions asked. There are organizations that track people's opinions of the various mail order companies, so you can check their reputation before you purchase anything. If we want to encourage other gardeners to plant a wider variety of plants, we have to display them in our gardens first. The extra cost of shipping is just the price we can choose to pay for something unusual or extra special. Also, once you have one of those special plants, you can save seed or take cuttings to propagate that plant and make the investment even more valuable. To each his own, but I've been very pleased by my on-line purchases. But, I don't have time to search the local nurseries. It's much easier for me to peruse the on-line catalogues at midnight and arrive home from work to find a carefully packed box on my door step. Good luck to everyone and enjoy your gardens.

Martha

Sanguisorba obtusa

Here is a link that might be useful: GardenWeb