Where I live the average life span of a perennial is three years. Yes they come back year after year but not always forever. It is very important to divide short lived perennials here every three years to keep them going strong. Many long lived perennials are available so it pays to do a little planning when creating your garden beds. Some of the long lived perennials in my garden are iris, hydrangea, hosta, peonia, shasta daisy Becky, Russian sage, lambs ear, geranium, Japanese anenome, sedum autumn joy, blue salvia, sedum angelina, and daylily.

Regular old purple coneflowers (echinacea), coreopsis moonbeam, lobelia cardinalis (one is on year 6 now), butterfly weed (A. tuberosa), hardy hibiscus, hydrangea (now year 5 I think).

I sure wish I could get lavender to live longer.

Karen

C. Moonbeam hasn't done well for me but C. 'Sienna Sunset' has. gaillardia, English lavender (not the French), hardy Hibs, Rose of Sharon, Buddleja, rosemary, sedums and sempervivums, daylilies, iris, phlox, Tennesse coneflower and Tennesse aster (of course, I'm in Tennessee ), other cones, lamb's ears, Indian pink, Joy Pye weed and chocolate eupatorium, EE, cannas, persecarias, horseradish, agastache, 4 o'clocks, mirabilis jalapa, milkweeds, and hardy bamboo. Some are true perennials and some just faithfully reseed each year to make a nice display. But next year -- year 4 -- will tell the tale for some of them.

coneflowers and columbine have been reseeding many years in my garden too. All coneflowers are gone now but the columbine are going strong. I just love the way the seeds rattle in the garden.

Species geranium live a long time both here and up North.

I just happened to be making up seed labels from my only Delphinium. (D. elatum "Pacific Giant"). I got 6 teaspoons of seed from one 6' plant!

Some source said these would be short-lived Perennials in cold climates (only a few years in Zone 2), but would last 5 or more years in Zone 7 and warmer.

I'm in Zone 8, but I'll be keeping my eyes open for reseeding, and divide if it doesn't re-seed successfully. My slugs seem to have identified young Delphiniums as their favorite food ever.

Rick, I have never had a delphinium cultivar live over winter here. I do have one that is some sort of species, and it lives, but does not increase.

Susan, I am in zone 5/6. It used to be 5 until they redrew the lines of zones, then it says I am 6. However, I have pretty harsh conditions out here in the country, and we are near the highest elevation in the county. So, I consider my garden zone 5.

Forgive my spelling -am using an iPad right now, and it is not easy to have one window for looking things up and one for posting.

In addition to the ones you mentioned:
Wormwood (I think that is it )
Epimedium
Hardy ginger - I have the native and European
Pinela Dragon Tales
Monarda
Spiderwort
Monkshood
Spuria iris
Certain heuchera -newer ones don't seem to be hardy
Clematis
Balloon flower
Phlox
Dianthus
Celone -turtlehead
Certain hardy ferns
Hexastylus
Pulmonaria
Soloman's Seal
Species primrose
Ligularia -I have Britt Marie Crawford
Astillbe
Catmint

I know I have many more that are 8-10 years old....just cannot think off the top of my head. I never divide anything but my daylilies.

Sandi I have your exact situation. Won't even pretend a zone 6 is going to make it through winter unless it is extremely mild. I have had my arm twisted a time or two but generally try to stick to zone 5.

That is such a great and comprehensive list, Juli!

Thanks. I will try to notice more when I am out to add to the list. Many that I grow were already mentioned by others.

Juli I'm glad you mentioned that because it means gardeners are finding them very reliable and long blooming☺ Must say I had a good time googling to learn more about some of the plants you are growing. Guess I need to start checking the data base on ATP more often as well

Whew! Talk about long lists. I'm glad its the off season so that I can go thru my plant inventory. What a great feature this would be for the database. Or is it too climate/conditions dependent?

I'm not sure, but I agree it would be a great addition to the database at some point in time. Some of the gardening guides have a section for drought-tolerant and perhaps something could indeed be added to the database for growing conditions. Maybe the way Dave added the Primary plant types section. It would definitely need to list zones too, I think.

You can always add things like "drought tolerant" as a comment.

Karen

I've given up on my Britt Marie Crawford. Do Ligularia need lots of water, or your not supposed to let the soil dry out? Both?

Best grown in humusy, organically rich, medium to wet soils in part shade to full shade. Plants must have moist soils that never dry out. Plants benefit from regular, deep watering. Plants prefer cool summer locations and generally do not perform well in the hot and humid summers of the deep South. Plants need a location with afternoon shade in the St. Louis area. Foliage will wilt in too much sun. Site plants in areas protected from strong winds.
Even with adequate moisture, leaf wilting usually occurs in hot summer climates, particularly when the plant is exposed to too much sun.

Ligularia love moisture and boggy conditions. I had one under deep shade, in humusy conditions and it was a happy guy there. Cut some nearby branches down, got too much sun and it was